HCG Calculator

An HCG calculator is a tool that measures the doubling time between two beta HCG blood tests to assess pregnancy viability. Enter your two HCG values with their test dates and times to calculate how quickly your hormone levels are rising. The calculator compares your doubling rate to normal ranges for your pregnancy stage, helping you understand if progression is typical. Most pregnancies show HCG doubling every 48 to 72 hours in early weeks.

Beta HCG refers to the beta subunit of human chorionic gonadotropin hormone measured in blood pregnancy tests. Beta HCG and HCG are essentially the same when discussing pregnancy tests. Blood tests measure beta HCG and are more accurate than urine tests, detecting levels as low as 1 mIU/mL. Urine tests typically detect HCG at 20 to 25 mIU/mL. Beta HCG blood tests provide exact numerical values needed for doubling time calculations.

Normal HCG doubling time varies by pregnancy stage and HCG level. In weeks 4 to 6 when HCG is below 1,200 mIU/mL, expect doubling every 48 to 72 hours. Between 1,200 and 6,000 mIU/mL, doubling slows to every 72 to 96 hours. Above 6,000 mIU/mL, doubling may take 96 hours or longer. As pregnancy advances past 8 weeks, HCG levels plateau and may even decrease slightly while remaining normal. Individual variation exists, but consistent doubling within these ranges typically indicates healthy pregnancy progression.

You cannot determine exact gestational age from HCG levels alone due to significant individual variation. At 4 weeks from last menstrual period, HCG ranges from 5 to 426 mIU/mL. At 5 weeks, ranges span 18 to 7,340 mIU/mL. At 6 weeks, levels vary from 1,080 to 56,500 mIU/mL. This wide variation means a level of 1,000 mIU/mL could indicate anywhere from late 4 weeks to early 6 weeks. Dating ultrasound performed after 6 weeks provides accurate gestational age. Track HCG doubling time rather than absolute values for pregnancy viability.

Calculate weeks from your last menstrual period (LMP) first day, then compare HCG to expected ranges. Ovulation typically occurs 14 days after LMP start. At 4 weeks LMP (2 weeks post ovulation), expect 5 to 426 mIU/mL. At 5 weeks LMP, expect 18 to 7,340 mIU/mL. At 6 weeks LMP, expect 1,080 to 56,500 mIU/mL. Remember these are population averages with wide normal variation. Focus on appropriate doubling time for your HCG level rather than comparing to average ranges.

HCG levels provide rough estimates but cannot pinpoint exact gestational age. A level of 100 mIU/mL typically indicates 4 to 5 weeks pregnant. A level of 1,000 mIU/mL suggests 4 to 6 weeks. A level of 10,000 mIU/mL indicates 5 to 7 weeks. Wide individual variation exists within normal pregnancies. Some women have lower HCG throughout pregnancy while others run higher. Dating ultrasound after 6 weeks measuring crown rump length provides accurate dating within 3 to 5 days.

After IVF embryo transfer, first beta HCG test occurs 9 to 14 days post transfer. For 5 day blastocyst transfer, test at 9 to 10 days post transfer (9dp5dt or 10dp5dt). Expected levels at 14dp5dt range from 50 to 500 mIU/mL, with average around 200 mIU/mL. Levels above 100 mIU/mL at 14dp5dt generally indicate good prognosis. Day 3 embryo transfers test at 14 days post transfer (14dp3dt). IVF pregnancies follow similar doubling patterns to natural conception, expecting 48 to 72 hour doubling initially.

Expected HCG after embryo transfer depends on transfer day and test timing. For day 5 blastocyst transfer: 9dp5dt expect 25 to 100 mIU/mL, 11dp5dt expect 50 to 200 mIU/mL, 14dp5dt expect 100 to 500 mIU/mL, 16dp5dt expect 200 to 1,000 mIU/mL. For day 3 transfer, add 2 days to these timelines. Frozen embryo transfers (FET) show similar patterns. Focus on doubling time between tests rather than comparing to others. Some successful pregnancies start with lower initial values but show appropriate doubling.

IVF pregnancies follow identical HCG doubling patterns as natural conception. Expect doubling every 48 to 72 hours when HCG is below 1,200 mIU/mL. Between days 14 and 16 post 5 day transfer, HCG should approximately double. Slower initial rise or faster doubling does not necessarily indicate problems. Some IVF pregnancies show slightly different patterns due to assisted hatching or embryo quality factors. Serial measurements showing consistent rise matter more than absolute values or exact doubling time.

Frozen embryo transfer (FET) HCG patterns match fresh transfer expectations. Test first beta 9 to 14 days after FET depending on embryo stage. Natural cycle FET may show slightly different initial values than medicated cycles due to progesterone differences. Expected doubling remains 48 to 72 hours regardless of fresh or frozen transfer. Track with same calculator method entering two beta values 48 hours apart. Success rates correlate with appropriate doubling rather than absolute starting values.

Test HCG 14 days after IUI insemination for accurate results. Positive pregnancy shows HCG above 25 mIU/mL. Expected levels at 14 days post IUI range from 25 to 100 mIU/mL for singleton pregnancy. If trigger shot was used, wait full 14 days as 10,000 IU trigger takes 10 to 14 days to clear. Levels should then double every 48 to 72 hours. IUI pregnancies follow identical HCG patterns to natural conception. Low initial values with appropriate doubling indicate viable pregnancy.

Twin pregnancies typically produce 30 to 50 percent higher HCG than singleton pregnancies, though ranges overlap significantly. At 4 weeks, twins average 50 to 600 mIU/mL versus singleton 5 to 426 mIU/mL. At 5 weeks, twins range 200 to 10,000 mIU/mL versus singleton 18 to 7,340 mIU/mL. High HCG alone cannot diagnose twins as some singleton pregnancies have elevated levels. Twins maintain standard 48 to 72 hour doubling time despite higher absolute values. Ultrasound at 6 weeks definitively confirms multiple pregnancy.

Twin HCG ranges by week from LMP show higher values than singletons but wide variation exists. Week 4: 50 to 600 mIU/mL for twins versus 5 to 426 for singleton. Week 5: 200 to 10,000 mIU/mL for twins versus 18 to 7,340 for singleton. Week 6: 2,000 to 85,000 mIU/mL for twins versus 1,080 to 56,500 for singleton. Week 7 to 8: 10,000 to 300,000 mIU/mL for twins. Remember significant overlap occurs between twin and singleton ranges. Some twin pregnancies have normal singleton range HCG throughout.

Twins do not cause faster HCG doubling despite higher absolute levels. Both singleton and twin pregnancies follow 48 to 72 hour doubling when HCG is below 1,200 mIU/mL. Twins simply start with higher initial values then double at the normal rate. The doubling time calculation remains identical regardless of singleton or multiple pregnancy. Focus on consistent doubling pattern rather than comparing absolute values to twin ranges. Many successful twin pregnancies have HCG within normal singleton ranges.

Calculate HCG doubling time using this formula: Doubling Time (hours) = (time between tests × log 2) / log(HCG2/HCG1). For example, if HCG rises from 100 to 250 mIU/mL in 48 hours: (48 × 0.693) / log(250/100) = (48 × 0.693) / 0.398 = 83.5 hours doubling time. Our calculator performs this automatically. Enter two HCG values with dates and times for instant results. Normal doubling is 48 to 72 hours early in pregnancy, slowing as levels increase.

HCG should rise at least 53 percent in 48 hours during early pregnancy when levels are below 1,200 mIU/mL. Ideal doubling (100 percent increase) occurs in many but not all normal pregnancies. Minimum viable rise is 35 percent in 48 hours when HCG exceeds 6,000 mIU/mL. Calculate percentage rise: ((HCG2 – HCG1) / HCG1) × 100. For example, rise from 100 to 180 mIU/mL equals 80 percent increase, which is normal. Consistent rise patterns matter more than exact percentages.

Not all normal pregnancies show exact doubling in 48 hours. Minimum acceptable rise is 53 percent in 48 hours when HCG is below 1,200 mIU/mL. Above 1,200 mIU/mL, doubling normally takes 72 to 96 hours. Above 6,000 mIU/mL, even slower rise is normal. Calculate your exact doubling time using our calculator. If doubling time exceeds 72 hours with HCG below 1,200 mIU/mL, consult your doctor for ultrasound evaluation. Some viable pregnancies have slower initial doubling but accelerate later.

Slow HCG doubling becomes normal as pregnancy progresses and levels increase. After 6 to 7 weeks gestation or when HCG exceeds 6,000 mIU/mL, doubling may take 96 hours or longer. Between weeks 8 to 10, HCG often plateaus around 50,000 to 100,000 mIU/mL. After 10 weeks, HCG may decrease while pregnancy remains healthy. However, slow doubling before 6 weeks with HCG below 1,200 mIU/mL warrants evaluation. Context matters: consistent slow rise may indicate ectopic pregnancy or miscarriage risk.

After methotrexate for ectopic pregnancy, HCG should decrease 15 percent between day 4 and day 7 post injection. Initial rise in first 4 days occurs in 60 percent of cases before declining. Continue weekly HCG monitoring until levels reach below 5 mIU/mL, confirming complete resolution. Treatment success shows 50 percent decrease within 2 weeks. If HCG fails to drop 15 percent by day 7 or increases after day 4, second methotrexate dose or surgery may be needed. Complete clearance typically takes 2 to 8 weeks depending on initial HCG level.

Ectopic pregnancy often shows abnormal HCG patterns including slower than expected doubling exceeding 72 hours with low HCG levels, plateauing levels without appropriate rise, or HCG below 1,500 mIU/mL when transvaginal ultrasound shows no intrauterine gestational sac. The discriminatory zone is 1,500 to 2,000 mIU/mL, above which intrauterine pregnancy should be visible on ultrasound. Below this level with abnormal doubling suggests ectopic risk. However, 15 percent of ectopic pregnancies show normal initial doubling, requiring clinical correlation with symptoms and ultrasound findings.

Miscarriage typically shows declining HCG or inadequate rise. Doubling time exceeding 72 hours with HCG below 1,200 mIU/mL suggests increased miscarriage risk. Plateauing or decreasing levels confirm pregnancy loss. After miscarriage, HCG should drop 50 percent every 48 to 72 hours. Complete miscarriage confirmed when HCG returns below 5 mIU/mL. Time to negative varies from 1 to 9 weeks depending on initial level and miscarriage type. Retained tissue shows slower decline. Serial monitoring ensures complete resolution without need for intervention.

Men on testosterone replacement therapy (TRT) use HCG (human chorionic gonadotropin) to maintain fertility and testicular function while receiving exogenous testosterone. TRT suppresses the body’s natural production of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), leading to testicular atrophy and halted sperm production. HCG mimics LH action, stimulating the testes to continue producing testosterone naturally and maintaining spermatogenesis. Typical HCG dosing for men on TRT is 250 to 500 IU via subcutaneous injection 2 to 3 times weekly. This preserves testicular size, maintains fertility potential, and prevents the complete shutdown of the hypothalamic-pituitary-gonadal axis. Men not on TRT should have HCG levels below 5 mIU/mL. Elevated HCG in men not receiving treatment may indicate testicular cancer, particularly germ cell tumors, requiring immediate medical evaluation. Some transgender men transitioning with testosterone may also use HCG if fertility preservation is desired.

Test HCG at these optimal times for accuracy: 14 days after ovulation for natural conception, 14 days after IUI insemination, 9 to 14 days after embryo transfer depending on embryo age, or after missed period. For monitoring doubling, test every 48 to 72 hours at consistent times. Morning blood draws provide most consistent results. Stop serial HCG monitoring once ultrasound confirms intrauterine pregnancy with heartbeat, typically around 6 to 7 weeks. Earlier testing may yield false negatives as HCG needs time to reach detectable levels.

HCG levels by days past ovulation show wide normal variation. At 10 DPO, levels range from undetectable to 50 mIU/mL. At 12 DPO, expect 10 to 100 mIU/mL. At 14 DPO, normal spans 25 to 200 mIU/mL. At 16 DPO, ranges are 50 to 500 mIU/mL. At 18 DPO, expect 100 to 1,000 mIU/mL. At 21 DPO, levels reach 500 to 5,000 mIU/mL. Home pregnancy tests detect around 25 mIU/mL, explaining why testing before 12 DPO often shows negative despite pregnancy. Track doubling rather than comparing to DPO averages.

HCG trigger shot clears at approximately 1,000 IU per day from your system. Standard 10,000 IU trigger takes 10 to 14 days for complete clearance. The 5,000 IU trigger clears in 7 to 10 days. The 250 microgram Ovidrel (6,500 IU equivalent) clears in 8 to 10 days. Test pregnancy no sooner than 14 days post trigger to avoid false positive from residual trigger HCG. Some women metabolize faster or slower affecting clearance time. If testing earlier, levels should exceed what trigger alone would produce, typically over 100 mIU/mL by day 14.

Normal HCG ranges by week from last menstrual period show wide variation between individuals. Week 3: 5 to 50 mIU/mL as implantation begins. Week 4: 5 to 426 mIU/mL with rapid initial rise. Week 5: 18 to 7,340 mIU/mL showing exponential growth. Week 6: 1,080 to 56,500 mIU/mL continuing rapid increase. Week 7 to 8: 7,650 to 229,000 mIU/mL approaching peak levels. Week 9 to 12: 25,700 to 288,000 mIU/mL plateauing at maximum. These ranges are extremely wide due to individual variation in HCG production. Some women maintain lower levels throughout normal pregnancy while others have consistently higher values. Focus on appropriate doubling time for your specific HCG level rather than comparing to average ranges, as a healthy pregnancy can fall anywhere within these broad parameters.

HCG levels alone cannot determine exact gestational age due to enormous individual variation in normal pregnancies. A level of 1,000 mIU/mL could indicate anywhere from 4 to 6 weeks pregnant depending on the individual. Similarly, 10,000 mIU/mL might represent 5 to 7 weeks gestation. These wide ranges exist because HCG production varies significantly between women based on factors including placental size, multiple pregnancy, individual hormone production rates, and implantation timing. Dating ultrasound performed after 6 weeks provides accurate gestational age within 3 to 5 days by measuring crown-rump length. Until ultrasound confirmation, use our calculator to track doubling time, which provides better pregnancy viability assessment than absolute HCG values. Remember that consistent appropriate doubling matters more than comparing your levels to population averages.

IVF pregnancies require specific HCG monitoring protocols based on embryo transfer timing. After IVF embryo transfer, first beta HCG test typically occurs 9 to 14 days post-transfer depending on embryo development stage. For 5-day blastocyst transfers, test at 9 to 10 days post-transfer (9dp5dt or 10dp5dt) for early results or wait until 14dp5dt for standard testing. Expected levels at 14dp5dt range from 50 to 500 mIU/mL, with average values around 200 mIU/mL. Levels above 100 mIU/mL at 14dp5dt generally indicate good prognosis for ongoing pregnancy. Day 3 embryo transfers require testing at 14 days post-transfer (14dp3dt). IVF pregnancies follow identical HCG doubling patterns to natural conception, expecting 48 to 72 hour doubling when levels are below 1,200 mIU/mL. Use our calculator by entering your beta HCG values from consecutive tests to track appropriate doubling.

Successful embryo transfer shows specific HCG patterns depending on transfer day and test timing. For fresh or frozen 5-day blastocyst transfers: 9dp5dt expect 25 to 100 mIU/mL indicating early implantation, 11dp5dt expect 50 to 200 mIU/mL showing progression, 14dp5dt expect 100 to 500 mIU/mL confirming pregnancy establishment, 16dp5dt expect 200 to 1,000 mIU/mL demonstrating continued growth. For day 3 transfers, add 2 days to these timelines. Frozen embryo transfers (FET) show similar patterns to fresh transfers. Most importantly, HCG should double every 48 to 72 hours regardless of starting value. Focus on consistent doubling time between tests rather than comparing absolute values to others, as some successful pregnancies start with lower initial values but show appropriate doubling. Single embryo transfers typically show lower initial HCG than multiple embryo transfers.

IVF beta HCG monitoring follows specific protocols for optimal pregnancy assessment. Test first beta 14 days post-retrieval for fresh transfers or 9 to 14 days post-transfer for frozen embryos. Repeat beta HCG 48 hours later to calculate doubling time. IVF pregnancies follow identical doubling patterns as natural conception: expect doubling every 48 to 72 hours when HCG is below 1,200 mIU/mL. Between days 14 and 16 post 5-day transfer, HCG should approximately double. Some IVF pregnancies show slightly different patterns due to assisted hatching, embryo quality factors, or endometrial receptivity. Continue monitoring with third beta if doubling is borderline. Serial measurements showing consistent rise matter more than absolute values or exact doubling time. Stop HCG monitoring once ultrasound confirms intrauterine pregnancy with cardiac activity around 6 to 7 weeks.

Frozen embryo transfer (FET) HCG calculations follow similar patterns to fresh transfers with minor protocol differences. Test first beta 9 to 14 days after FET depending on embryo stage and clinic protocol. Natural cycle FET may show slightly different initial values than medicated cycles due to endogenous versus exogenous progesterone effects. Programmed FET cycles with estrogen and progesterone supplementation typically show consistent HCG patterns. Expected doubling remains 48 to 72 hours regardless of fresh or frozen transfer. Track using same calculator method by entering two consecutive beta values 48 hours apart. FET success rates correlate with appropriate doubling rather than absolute starting values. Hatching or assisted hatching of frozen embryos doesn’t significantly alter expected HCG patterns. Some studies suggest FET may have slightly lower initial HCG than fresh transfers, but doubling rates remain identical.

IUI (intrauterine insemination) pregnancies show HCG patterns identical to natural conception. Test HCG 14 days after IUI procedure for accurate results, as testing earlier may yield false negatives. Positive pregnancy shows HCG above 25 mIU/mL, with expected levels at 14 days post-IUI ranging from 25 to 100 mIU/mL for singleton pregnancy. Higher initial values may suggest multiple pregnancy from multiple follicle development. If trigger shot was used for ovulation timing, wait full 14 days for testing as 10,000 IU trigger takes 10 to 14 days to clear completely from your system. After positive result, HCG should double every 48 to 72 hours. IUI with gonadotropin stimulation may show slightly higher initial HCG than natural cycle IUI. Track doubling time using our calculator with tests 48 hours apart. Low initial values with appropriate doubling indicate viable pregnancy.

Twin pregnancy HCG calculators use the same doubling time formula as singleton pregnancies but expect higher absolute values. Twin pregnancies typically produce 30 to 50 percent higher HCG than singletons, though ranges overlap significantly making diagnosis by HCG alone impossible. At 4 weeks from LMP, twins average 50 to 600 mIU/mL versus singleton 5 to 426 mIU/mL. At 5 weeks, twins range 200 to 10,000 mIU/mL versus singleton 18 to 7,340 mIU/mL. Despite higher levels, twins maintain standard 48 to 72 hour doubling time when HCG is below 1,200 mIU/mL. The calculator works identically: enter two HCG values with test dates to determine doubling time. High HCG alone cannot diagnose twins as some singleton pregnancies have elevated levels due to placental factors. Ultrasound at 6 weeks definitively confirms multiple pregnancy by visualizing separate gestational sacs.

Twin pregnancy HCG ranges show higher values than singletons but maintain enormous individual variation. Week 4 from LMP: twins 50 to 600 mIU/mL versus singleton 5 to 426 mIU/mL. Week 5: twins 200 to 10,000 mIU/mL versus singleton 18 to 7,340 mIU/mL. Week 6: twins 2,000 to 85,000 mIU/mL versus singleton 1,080 to 56,500 mIU/mL. Week 7 to 8: twins 10,000 to 300,000 mIU/mL showing continued elevation. Week 9 to 12: twins may exceed 288,000 mIU/mL at peak. Remember significant overlap occurs between twin and singleton ranges throughout pregnancy. Some twin pregnancies maintain HCG within normal singleton range while some singletons have twin-level HCG. Doubling time remains 48 to 72 hours regardless of multiple pregnancy. These ranges apply to dizygotic (fraternal) and monozygotic (identical) twins equally.

Twin pregnancies do not cause faster HCG doubling despite producing higher absolute levels. Both singleton and twin pregnancies follow identical doubling patterns: 48 to 72 hours when HCG is below 1,200 mIU/mL, 72 to 96 hours between 1,200 and 6,000 mIU/mL, and over 96 hours above 6,000 mIU/mL. Twins simply start with higher initial values due to increased placental mass, then double at the normal rate. The doubling time calculation remains identical regardless of singleton or multiple pregnancy. Higher order multiples (triplets, quadruplets) also follow standard doubling patterns while producing even higher absolute HCG values. Focus on consistent doubling pattern rather than comparing absolute values to twin ranges. Many successful twin pregnancies have HCG within normal singleton ranges, making ultrasound the only definitive diagnostic method for multiple pregnancy.

The HCG doubling time formula calculates hours required for HCG to double: Doubling Time (hours) = (time between tests × log 2) / log(HCG2/HCG1). Breaking down the calculation: measure time between blood draws in hours, divide second HCG value by first HCG value, take the logarithm of that ratio, divide log(2) which equals 0.693 by the log of your ratio, then multiply by hours between tests. For example, if HCG rises from 100 to 250 mIU/mL in 48 hours: log(250/100) = log(2.5) = 0.398, then (48 × 0.693) / 0.398 = 83.5 hours doubling time. Our calculator performs this automatically providing instant results. Normal doubling is 48 to 72 hours early in pregnancy, slowing as levels increase above 1,200 mIU/mL.

Normal HCG rise percentages vary by timeframe and absolute HCG level. In 48 hours, minimum viable increase is 53 percent when HCG is below 1,200 mIU/mL, though ideal doubling represents 100 percent increase. Between 1,200 and 6,000 mIU/mL, expect 35 to 53 percent rise in 48 hours. Above 6,000 mIU/mL, even 35 percent increase in 48 hours can be normal as doubling slows. Calculate percentage rise using: ((HCG2 – HCG1) / HCG1) × 100. For 72 hour intervals, expect minimum 133 percent increase below 1,200 mIU/mL. Rise from 100 to 180 mIU/mL in 48 hours equals 80 percent increase, which falls within normal range. Consistent rise patterns matter more than exact percentages. Serial testing showing steady progression indicates healthy pregnancy development regardless of precise doubling time.

Normal HCG calculator results after 48 hours depend on your starting HCG level. Below 1,200 mIU/mL: expect 53 to 100 percent increase, with most pregnancies showing near-doubling. Between 1,200 and 6,000 mIU/mL: 35 to 53 percent rise is acceptable as doubling naturally slows. Above 6,000 mIU/mL: even 35 percent increase can be normal. Calculate using our tool by entering both values with exact test times. For example, rise from 500 to 950 mIU/mL in 48 hours shows 90 percent increase with 52-hour doubling time, perfectly normal for early pregnancy. Not all healthy pregnancies show exact 48-hour doubling. Focus on consistent upward trend rather than precise percentages. If doubling time exceeds 72 hours with HCG below 1,200 mIU/mL, consult your doctor for evaluation.

Not doubling every 48 hours can be normal depending on pregnancy stage and HCG level. After 6 to 7 weeks gestation or when HCG exceeds 6,000 mIU/mL, slower doubling becomes expected as placental growth stabilizes. Doubling may take 96 hours or longer at high levels. Between weeks 8 to 10, HCG often plateaus around 50,000 to 100,000 mIU/mL while pregnancy remains healthy. After 10 to 12 weeks, HCG may actually decrease as placental hormone production shifts. However, slow doubling before 6 weeks with HCG below 1,200 mIU/mL requires medical evaluation. Minimum acceptable rise is 53 percent in 48 hours during early pregnancy. Consistently slow rise or plateauing at low levels may indicate ectopic pregnancy or impending miscarriage. Context matters: evaluate doubling time relative to your specific HCG level and gestational age.

After methotrexate treatment for ectopic pregnancy, specific HCG monitoring protocols ensure treatment success. HCG should decrease 15 percent between day 4 and day 7 post-injection, confirming medication effectiveness. Initial paradoxical rise in first 4 days occurs in 60 percent of cases before declining, which doesn’t indicate treatment failure. Continue weekly HCG monitoring until levels reach below 5 mIU/mL, confirming complete resolution. Successful treatment shows 50 percent total decrease within 2 weeks. If HCG fails to drop 15 percent by day 7 or increases after day 4, second methotrexate dose may be needed. Approximately 20 percent require second dose. Complete clearance typically takes 2 to 8 weeks depending on initial HCG level. Higher starting HCG correlates with longer clearance time and increased likelihood of requiring surgical intervention.

Ectopic pregnancy displays characteristic abnormal HCG patterns requiring immediate medical attention. Most commonly, HCG shows inappropriately slow doubling exceeding 72 hours despite levels below 1,200 mIU/mL. Plateauing levels without appropriate rise suggest non-viable pregnancy location. The discriminatory zone concept states HCG above 1,500 to 2,000 mIU/mL should show intrauterine gestational sac on transvaginal ultrasound. Absence of intrauterine pregnancy above this threshold strongly suggests ectopic pregnancy. Additional warning signs include HCG rising less than 53 percent in 48 hours during early pregnancy, irregular doubling patterns with acceleration and deceleration, or HCG levels inappropriate for gestational age. However, 15 percent of ectopic pregnancies show normal initial doubling, requiring clinical correlation with symptoms including unilateral pelvic pain, vaginal bleeding, and shoulder tip pain indicating internal bleeding.

HCG calculator assists in confirming miscarriage and monitoring resolution. Impending miscarriage typically shows declining HCG or inadequate rise with doubling time exceeding 72 hours when HCG is below 1,200 mIU/mL. Plateauing or decreasing levels confirm pregnancy loss. After miscarriage diagnosis, HCG should drop 50 percent every 48 to 72 hours during active loss. Complete miscarriage is confirmed when HCG returns below 5 mIU/mL, indicating no retained tissue. Time to negative HCG varies from 1 to 9 weeks depending on initial level, miscarriage type, and completeness of tissue passage. Medical management with misoprostol shows similar HCG decline patterns to natural miscarriage. Retained products of conception show slower HCG decline or plateau above 5 mIU/mL. Serial monitoring ensures complete resolution without need for surgical intervention. D&C may be indicated if HCG plateaus or rises after initial decline.

HCG calculator for men serves different purposes than pregnancy monitoring, primarily tracking therapeutic HCG levels during testosterone replacement therapy (TRT). Men use HCG at 250 to 500 IU subcutaneous injection 2 to 3 times weekly to maintain fertility and prevent testicular atrophy during TRT. This preserves intratesticular testosterone production essential for spermatogenesis. HCG monitoring ensures appropriate dosing without excessive elevation. Target HCG levels during treatment vary by protocol but generally remain below female pregnancy ranges. Men not receiving HCG therapy should have levels below 5 mIU/mL. Elevated HCG in untreated men indicates potential testicular cancer, particularly nonseminomatous germ cell tumors producing HCG as tumor marker. Serial HCG monitoring tracks cancer treatment response. Some bodybuilders misuse HCG during anabolic steroid cycles, requiring medical supervision for safe discontinuation. Transgender men may use HCG for fertility preservation before or during testosterone therapy.

Optimal HCG testing timing ensures accurate calculator results and pregnancy assessment. For natural conception, test 14 days after ovulation when HCG reaches detectable levels above 25 mIU/mL. After timed intercourse or IUI, wait 14 days post-procedure. IVF requires specific timing: 9 to 14 days after embryo transfer depending on embryo development stage. Test after missed period if cycle timing unknown. For doubling time calculation, test every 48 to 72 hours maintaining consistent intervals. Morning blood draws between 7 to 9 AM provide most consistent results due to minimal diurnal variation. Maintain same time of day for serial tests. Stop serial HCG monitoring once transvaginal ultrasound confirms intrauterine pregnancy with cardiac activity, typically around 6 to 7 weeks gestation. Earlier testing may yield false negatives as HCG needs sufficient time post-implantation to reach detectable levels in blood.

HCG levels by days past ovulation (DPO) show predictable patterns with wide individual variation. Implantation typically occurs 6 to 12 DPO, initiating HCG production. At 10 DPO, levels range from undetectable to 50 mIU/mL in early implanters. By 12 DPO, expect 10 to 100 mIU/mL as more pregnancies become detectable. At 14 DPO (missed period day), normal spans 25 to 200 mIU/mL. By 16 DPO, ranges increase to 50 to 500 mIU/mL with established pregnancy. At 18 DPO, expect 100 to 1,000 mIU/mL showing exponential growth. By 21 DPO, levels reach 500 to 5,000 mIU/mL. Home pregnancy tests detecting 25 mIU/mL explain why testing before 12 DPO often shows negative despite conception. Blood tests detect as low as 1 mIU/mL but clinical significance requires levels above 5 mIU/mL. Track doubling time rather than comparing to DPO averages for pregnancy viability assessment.

HCG trigger shot for ovulation induction significantly impacts pregnancy test timing and calculator use. Standard 10,000 IU Pregnyl or Novarel trigger contains recombinant HCG clearing at approximately 1,000 IU per day. Complete clearance takes 10 to 14 days depending on individual metabolism. The 5,000 IU trigger clears in 7 to 10 days. Ovidrel 250 microgram (6,500 IU equivalent) clears in 8 to 10 days. Test pregnancy no sooner than 14 days post-trigger to avoid false positive from residual trigger HCG. Some women metabolize HCG faster or slower affecting clearance time. If testing before full clearance, pregnancy HCG levels should significantly exceed expected trigger residual. By day 14, trigger residual is negligible while true pregnancy shows levels above 50 to 100 mIU/mL. Serial testing helps distinguish rising pregnancy HCG from declining trigger levels. Use calculator only after confirming true pregnancy HCG, not trigger residual.

With 3 or more HCG tests, calculate doubling time between each consecutive pair. First test to second test gives one doubling time, second to third gives another. Consistent doubling times across all tests indicates normal progression. If doubling time varies significantly between test pairs, this may indicate abnormal pregnancy development. For example, if test 1 is 100, test 2 is 200 (48 hours later), and test 3 is 350 (48 hours after test 2), the first interval shows perfect doubling while the second shows slowing, warranting medical evaluation.

Graphing HCG levels on logarithmic scale shows doubling as a straight line. Plot days on horizontal axis and HCG values on vertical axis using log scale. Normal doubling appears as consistent upward slope. Flattening curve indicates slowing doubling. Declining line shows decreasing HCG. Visual trends help identify problems early. Most doctors use logarithmic graphs because linear graphs make early values invisible compared to later high values. Track at least 3 to 4 values for meaningful trend visualization.

Converting HCG units is straightforward: 1 IU/L equals 1 mIU/mL exactly. They are equivalent units used interchangeably by different labs. Some labs report in ng/mL where 1 ng/mL equals approximately 10 mIU/mL, though this conversion varies by specific HCG assay. Always confirm units with your lab. Most US labs use mIU/mL while some European labs prefer IU/L. Our calculator accepts either since they are identical measurements.

Calculate HCG percentage increase using this formula: ((Second HCG minus First HCG) divided by First HCG) times 100. For example, if HCG rises from 100 to 180 mIU/mL, the calculation is ((180 minus 100) divided by 100) times 100 equals 80 percent increase. Minimum viable increase is 53 percent in 48 hours during early pregnancy. Above 6,000 mIU/mL, 35 percent increase in 48 hours can be normal. Our calculator automatically shows percentage increase alongside doubling time.

HCG levels vary widely between individuals, making it impossible to define a single “correct” level for any given pregnancy stage. Normal ranges are extremely broad: at 4 weeks from last menstrual period, anywhere from 5 to 426 mIU/mL is considered normal. At 5 weeks, the range expands to 18 to 7,340 mIU/mL. Rather than focusing on absolute numbers, monitor your HCG doubling time which provides better pregnancy viability assessment. Your specific trend of rising HCG matters significantly more than comparing to population averages. Some women maintain lower HCG throughout healthy pregnancies while others run consistently higher. Use our calculator to track your doubling pattern rather than worrying about specific number targets.

HCG viability calculators assess pregnancy health by analyzing doubling time patterns rather than absolute values. Viable pregnancies typically show HCG doubling every 48 to 72 hours when levels are below 1,200 mIU/mL. This consistent exponential growth indicates proper placental development and hormone production. Slow rise with doubling time exceeding 72 hours at low HCG levels may indicate non-viable pregnancy including ectopic location or impending miscarriage. Plateauing levels suggest pregnancy loss. However, after 6 weeks or when HCG exceeds 6,000 mIU/mL, slower doubling becomes normal. The calculator cannot definitively diagnose pregnancy viability alone. Ultrasound after 6 weeks provides definitive answers by visualizing gestational sac, yolk sac, fetal pole, and cardiac activity. Always correlate HCG patterns with clinical symptoms and ultrasound findings for comprehensive assessment.

Determining if your HCG levels are normal requires analyzing doubling time rather than comparing to average ranges. Enter your two HCG values with precise test dates and times in our calculator above. The calculator will indicate if your doubling is fast, normal, or slow for your specific HCG level. Normal doubling varies by HCG range: below 1,200 mIU/mL expect 48 to 72 hour doubling, between 1,200 and 6,000 mIU/mL expect 72 to 96 hours, above 6,000 mIU/mL doubling may exceed 96 hours. Results display color-coded status (green for normal, yellow for fast, red for slow) with detailed interpretation. Remember that 15 percent of normal pregnancies fall outside typical doubling patterns initially but normalize later. Single abnormal result doesn’t confirm problems – serial monitoring provides better assessment.

Calculate expected HCG from your last menstrual period (LMP) by counting weeks from the first day of your last period. Ovulation typically occurs 14 days after LMP start, with implantation 6 to 12 days later. Expected HCG ranges by weeks from LMP: Week 3 (1 week post-conception): 5 to 50 mIU/mL as implantation begins. Week 4: 5 to 426 mIU/mL showing initial rise. Week 5: 18 to 7,340 mIU/mL with rapid increase. Week 6: 1,080 to 56,500 mIU/mL continuing exponential growth. Week 7 to 8: 7,650 to 229,000 mIU/mL approaching peak. These ranges assume 28-day cycles with day 14 ovulation. Irregular cycles affect timing. Early or late implantation shifts expected values by several days. Individual variation means your levels may fall anywhere within these broad ranges while remaining completely normal.

HCG production begins immediately at implantation when the embryo attaches to the uterine lining, typically 6 to 12 days post-ovulation. From implantation date, expect these progression patterns: Day 1 post-implantation: 1 to 5 mIU/mL as trophoblast cells begin hormone production. Day 3: 5 to 50 mIU/mL showing initial rise. Day 7: 25 to 100 mIU/mL reaching detectable levels on sensitive tests. Day 10: 50 to 500 mIU/mL with established production. Day 14: 100 to 5,000 mIU/mL showing exponential growth. Doubling begins immediately after implantation with 1.4 to 2 day doubling time initially. Some women experience implantation bleeding marking this event, though many have no symptoms. Early home pregnancy tests may detect HCG by 7 to 10 days post-implantation. Blood tests detect lower levels around day 3 to 5 post-implantation.

From conception (fertilization) date, add 6 to 12 days for typical implantation timing before HCG production begins. The fertilized embryo travels through the fallopian tube for 5 to 6 days before reaching the uterus, then requires 1 to 6 additional days for implantation. Expected HCG from conception: Days 1 to 6: 0 mIU/mL as embryo travels to uterus. Days 6 to 12: 0 to 5 mIU/mL depending on implantation timing. Day 14 post-conception: 25 to 100 mIU/mL after implantation establishes. Day 18: 50 to 500 mIU/mL with active production. Day 21: 100 to 5,000 mIU/mL showing rapid rise. Day 28: 1,000 to 50,000 mIU/mL approaching peak growth phase. Track doubling time starting from first positive test rather than trying to calculate from conception, as implantation timing varies significantly between pregnancies.

Calculate HCG expectations from known ovulation date, remembering implantation occurs 6 to 12 days post-ovulation (DPO). Before implantation, HCG remains at zero. Expected progression from ovulation: 1 to 5 DPO: 0 mIU/mL as fertilization and early development occur. 6 to 8 DPO: 0 to 5 mIU/mL for earliest implanters. 10 DPO: 5 to 50 mIU/mL possible in early pregnancies. 12 DPO: 10 to 100 mIU/mL as more pregnancies become detectable. 14 DPO (missed period): 25 to 200 mIU/mL typical range. 16 DPO: 50 to 500 mIU/mL with established pregnancy. 18 DPO: 100 to 1,000 mIU/mL. 21 DPO: 500 to 5,000 mIU/mL. Most women won’t have detectable HCG before 10 DPO. Home pregnancy tests reliably detect pregnancy by 12 to 14 DPO when HCG exceeds 25 mIU/mL.