Beta hCG Calculator

Human chorionic gonadotropin (hCG) is the pregnancy hormone produced by the developing placenta after implantation. It's what pregnancy tests detect. In a healthy pregnancy, hCG levels rise rapidly during the first trimester, roughly doubling every 48-72 hours during the earliest weeks. After you get a positive result on a pregnancy test, blood tests can measure exact hCG levels to monitor early pregnancy progression.

Your healthcare provider may order beta hCG blood tests to monitor early pregnancy, especially after IVF, previous miscarriage, or if there's concern about ectopic pregnancy or miscarriage. Two tests taken 48-72 hours apart help assess whether pregnancy is progressing normally. The first test tells you the baseline level, while the second test shows whether levels are rising appropriately.

The doubling pattern is most predictable when levels are below 1,200 mIU/ml. As hCG rises higher, doubling slows. Above 6,000 mIU/ml, the doubling time extends to 96+ hours, and ultrasound becomes more useful than blood tests for tracking pregnancy. By this point, you should be around 5-6 weeks pregnant based on your gestational age, and ultrasound can visualize the gestational sac.

When you enter two hCG values and their test dates, the calculator determines how many hours it takes for your levels to double. In very early pregnancy (when levels are under 1,200 mIU/ml), normal doubling time is 48-72 hours. If your result falls in this range, it suggests healthy early pregnancy progression. Doubling times faster than 48 hours can be normal too, and sometimes occur in twin pregnancies, though hCG alone can't diagnose multiples.

As your starting hCG level increases, expect longer doubling times. Between 1,200-6,000 mIU/ml, doubling slows to 72-96 hours, which is perfectly normal. Above 6,000 mIU/ml, doubling can take up to 96-120 hours or longer. This slowdown doesn't mean anything is wrong - it's the natural pattern as pregnancy advances. At these higher levels, most doctors switch from blood tests to ultrasound for monitoring.

If your doubling time is significantly slower than expected for your starting level, your healthcare provider will likely order additional testing. Slow rises can indicate problems like ectopic pregnancy or impending miscarriage, but they require medical evaluation to interpret properly. Never try to diagnose problems based on hCG alone - abnormal doubling times need follow-up ultrasound and clinical assessment.

Most healthy pregnancies don't require serial hCG testing. If you have a regular menstrual cycle, positive home test, and no concerning symptoms, your doctor will likely skip blood work and just schedule your first prenatal visit for 8-10 weeks. Blood tests become important in specific situations where early monitoring is needed to assess pregnancy viability or rule out problems.

After IVF or IUI fertility treatments, clinics routinely order beta hCG tests because they need to confirm pregnancy before you stop certain medications. The first blood test (often called "beta day") typically happens 9-14 days after embryo transfer, depending on embryo age at transfer. A second test 48 hours later checks that levels are rising appropriately. If you've had previous ectopic pregnancy, your doctor may also want early hCG monitoring to establish that the pregnancy is in the correct location.

Women with a history of miscarriage often request hCG testing for reassurance in a new pregnancy. While rising hCG is a good sign, remember that miscarriage can still occur even with normal doubling times in early pregnancy. Conversely, some healthy pregnancies have slightly slower rises and turn out fine. hCG is just one data point - ultrasound confirmation of a heartbeat around 6-7 weeks is more definitive. Track your overall pregnancy timeline with our pregnancy calendar to see when key milestones should occur.

hCG production starts immediately after the embryo implants in your uterine lining. Implantation typically occurs 6-12 days after ovulation (most commonly 8-10 days past ovulation). Right after implantation, hCG levels are extremely low - often just 2-5 mIU/ml. The hormone then begins its characteristic doubling pattern, increasing rapidly over the following days and weeks.

At 10 DPO (days past ovulation), average hCG in a pregnant woman might be 10-15 mIU/ml, detectable by early pregnancy tests but still very low. By 12 DPO, average levels reach 25-50 mIU/ml. At 14 DPO (the day of your missed period), levels typically range from 50-100 mIU/ml, high enough for any standard pregnancy test to detect. This exponential rise continues through early pregnancy.

Peak hCG levels occur around 10-12 weeks of pregnancy, often reaching 100,000-200,000 mIU/ml or even higher. After this peak, hCG gradually declines to a lower plateau that persists throughout the second and third trimesters. This decline is normal and doesn't indicate problems - it simply reflects that the placenta is now well-established and doesn't need as much hCG to maintain pregnancy. Want to know how far along you are? Use our pregnancy week calculator.

A single low hCG reading doesn't automatically mean miscarriage or ectopic pregnancy. hCG levels vary enormously between healthy pregnancies. One woman might have 50 mIU/ml at 14 DPO while another has 200 mIU/ml - both are normal. The absolute number matters less than the pattern of rise. As long as your levels are doubling every 48-72 hours (for starting levels under 1,200), the pregnancy is most likely progressing normally regardless of whether your numbers are on the lower or higher end.

Lower-than-average hCG can sometimes indicate incorrect pregnancy dating. If you ovulated later than expected, you're not as far along as you thought, which means lower hCG is actually appropriate for your true gestational age. This is especially common in women with irregular cycles. A dating ultrasound can clarify how far along you actually are. Once dates are corrected, hCG levels usually fall within normal range for that stage.

Truly low hCG that's rising too slowly can indicate ectopic pregnancy (pregnancy implanted outside the uterus, usually in the fallopian tube) or impending miscarriage. Ectopic pregnancy is a medical emergency requiring immediate treatment. If your doubling time is slow and you experience abdominal pain or bleeding, call your doctor right away. They'll likely order an ultrasound to check pregnancy location. Learn when to expect your conception date to better track your timeline.

Twin and triplet pregnancies often produce higher hCG levels than singleton pregnancies because there are two or three placentas producing the hormone. On average, twin pregnancies have hCG levels 30-50% higher than singletons at the same gestational age. This means faster doubling times are common in multiple pregnancies, sometimes doubling in less than 48 hours in very early pregnancy.

However, you cannot diagnose twins based on hCG levels alone. The ranges for singleton and twin pregnancies overlap significantly. A woman with hCG of 300 at 14 DPO might be having twins, or she might just be on the higher end of normal for a singleton pregnancy. Similarly, some twin pregnancies have hCG levels that fall squarely in the "normal singleton" range. Ultrasound is the only way to definitively confirm twins - you need to actually see two gestational sacs or two heartbeats.

High hCG can also occur in singleton pregnancies with no special meaning - it's just individual variation. Some placentas naturally produce more hCG than others. High levels don't predict a healthier pregnancy or stronger baby. The only clinical significance of very high hCG is that it's associated with increased nausea and vomiting in early pregnancy, since hCG is believed to trigger morning sickness symptoms.

IVF patients almost always get beta hCG blood tests because clinics need to confirm pregnancy before stopping progesterone and other support medications. The timing of the first beta test depends on when embryo transfer occurred. For a 5-day blastocyst transfer, first beta is typically 9 days after transfer (9dp5dt). For 3-day embryo transfer, it's usually 12 days post-transfer. These timings give hCG enough time to rise to detectable levels after implantation.

Expected hCG levels after IVF transfer vary based on days post-transfer. At 9dp5dt, hCG above 50 mIU/ml is generally considered a good sign, though successful pregnancies can start lower. At 11dp5dt, levels are usually over 100 mIU/ml. At 14dp5dt, hCG typically exceeds 200 mIU/ml in healthy pregnancies. The second beta, 48 hours after the first, should show appropriate doubling. Many IVF clinics will order a third beta to confirm the upward trend continues.

For women who used trigger shots (hCG injections) as part of fertility treatment, you need to wait until the trigger shot is out of your system before testing. Trigger shots contain hCG and will cause false positive pregnancy tests. Most 10,000 IU trigger shots clear within 10-14 days. Your clinic will tell you when it's safe to test or will schedule your beta for after the trigger has cleared. Calculate your IVF due date with our specialized IVF calculator.

Once your hCG reaches 6,000-10,000 mIU/ml, further blood testing becomes less useful. At these levels, you're typically 5-6 weeks pregnant, and ultrasound can now visualize the gestational sac and confirm pregnancy location in the uterus. Ultrasound provides much more information than blood tests at this stage - it shows whether there's a yolk sac, whether a heartbeat is visible, and whether pregnancy is developing appropriately.

Your doctor will schedule your first ultrasound once hCG levels are high enough, usually between 5-7 weeks gestation. At 6 weeks, you should see a heartbeat in most pregnancies. This visible heartbeat is more reassuring than any hCG number because it confirms a viable intrauterine pregnancy. After heartbeat is confirmed, there's no reason to continue checking hCG levels unless you develop concerning symptoms.

Some women become fixated on hCG numbers in early pregnancy, testing repeatedly and worrying about every fluctuation. This can create unnecessary anxiety. Remember that hCG is just a screening tool for very early pregnancy. Once you've confirmed rising levels and ruled out ectopic pregnancy, the best approach is to wait for your first ultrasound. The weeks between positive test and first ultrasound are hard, but constantly checking hCG won't change the outcome - it just prolongs the waiting game. Use our pregnancy month calculator to track your overall progress.