HCG Levels Calculator

Track your HCG hormone levels during early pregnancy and understand your test results. Check if levels are low, normal, or high for your stage of pregnancy, and calculate HCG doubling time between two readings.

📊 Single HCG Level Check

HCG Level mIU/mL

Weeks Pregnant

⏱️ HCG Doubling Time

Enter two HCG readings with their dates to calculate doubling time. HCG normally doubles every 48–72 hours in early pregnancy.

First HCG Level mIU/mL

First Reading Date

Second HCG Level mIU/mL

Second Reading Date

Real-World HCG Level Examples

🤰 Early Pregnancy — 4 Weeks

A woman at 4 weeks pregnant has an HCG level of 120 mIU/mL.

Reference Range: 5–426 mIU/mL

Assessment: Normal

This level falls well within the expected range. HCG levels vary widely in early pregnancy.

📈 Rising HCG with Doubling Time

First reading on Monday: 50 mIU/mL at 5 weeks

Second reading on Wednesday (48 hours later): 120 mIU/mL

Doubling Time: ≈ 38 hours (Normal)

Excellent doubling time under 48 hours — indicates a healthy early pregnancy.

🔬 Higher HCG Levels — 6 Weeks

A woman at 6 weeks pregnant has an HCG level of 32,000 mIU/mL.

Reference Range: 1,080–56,500 mIU/mL

Assessment: Normal

Although higher than early weeks, this level is still within the normal 6-week range.

⚠️ Low HCG Level — When to Seek Guidance

A woman at 6 weeks pregnant has an HCG level of 200 mIU/mL.

Reference Range: 1,080–56,500 mIU/mL

Assessment: Low

Levels below the reference range may warrant further evaluation by a healthcare provider.

Understanding HCG Levels in Pregnancy

Human Chorionic Gonadotropin (HCG) is a hormone produced by the placenta shortly after implantation. It is the hormone detected by pregnancy tests and is commonly measured to monitor the health and progression of early pregnancy.

HCG Reference Ranges by Week

Weeks of Pregnancy	Reference Range (mIU/mL)
3 weeks	5–50
4 weeks	5–426
5 weeks	18–7,340
6 weeks	1,080–56,500
7–8 weeks	7,650–229,000
9–12 weeks	25,700–288,000
13–16 weeks	13,300–254,000
17–24 weeks	4,060–165,400
25–40 weeks	3,640–117,000

HCG Doubling Time = (Δt × ln 2) ÷ ln(HCG₂ ÷ HCG₁)

Where Δt is the time between readings. Normal doubling time: 48–72 hours in early pregnancy.

What HCG Levels Mean

Low HCG: Levels below the reference range may indicate a very early pregnancy, possible miscarriage, or ectopic pregnancy. Always consult your provider.

Normal HCG: Levels within the reference range suggest the pregnancy is developing as expected for that gestational stage.

High HCG: Levels above the reference range may indicate a multiple pregnancy (twins/triplets), inaccurate dating, or molar pregnancy. Consult your provider.

Doubling Time: In early pregnancy (up to 6 weeks), HCG levels typically double every 48–72 hours. Slower doubling may warrant monitoring.

Tips for Accurate HCG Tracking

📋 Use the Same Lab

HCG levels can vary between different laboratories. For consistent tracking, use the same lab for all your readings.

⏰ Consistent Timing

Take blood tests at the same time of day when comparing readings. HCG levels can fluctuate slightly throughout the day.

📊 Track Trends, Not Single Values

A single HCG level is less informative than the trend over time. Focus on whether levels are rising appropriately.

🩺 Always Consult Your Doctor

HCG levels are just one piece of information. Your healthcare provider will interpret results alongside ultrasound and other clinical findings.

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Level Assessment

Instantly check if your HCG level is low, normal, or high for your specific week of pregnancy based on medical reference ranges.

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Doubling Time

Calculate HCG doubling time between two readings with dates. A key indicator of early pregnancy health.

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Reference Ranges

Comprehensive HCG reference ranges from 3 weeks to 40 weeks of pregnancy based on standard medical guidelines.

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Women's Health Tool

Part of our Women's Health & Pregnancy suite designed to support expecting mothers with evidence-based information.

What is HCG?

Human Chorionic Gonadotropin (HCG) is a hormone produced by the placenta after implantation. Often called the "pregnancy hormone," HCG is what home pregnancy tests detect in urine. HCG levels rise rapidly in early pregnancy, typically doubling every 48–72 hours during the first few weeks. This rapid rise is essential for maintaining the corpus luteum, which produces progesterone needed to sustain the pregnancy.

HCG levels are measured through blood tests (quantitative HCG or beta HCG) and reported in milli-International Units per milliliter (mIU/mL). Because HCG levels vary widely between individuals and even between different pregnancies for the same person, doctors focus more on the trend over time rather than a single value. Our calculator uses standard reference ranges to help you understand where your levels fall compared to typical values for each week of pregnancy.

Understanding Your Results

Our HCG Levels Calculator provides two complementary tools. The Single Level Check compares one HCG reading against the standard reference range for your week of pregnancy, classifying it as low, normal, or high. The Doubling Time Calculator takes two readings with dates and computes the doubling time using the standard exponential growth formula. In early pregnancy (before 6–8 weeks), a doubling time under 72 hours is generally considered reassuring, while slower doubling may indicate the need for closer monitoring by your healthcare provider.

Why Track HCG Levels?

Monitoring HCG levels can provide valuable information about early pregnancy health. Here are the key reasons why HCG tracking is commonly recommended:

🫀 Confirm Pregnancy Viability

Rising HCG levels indicate that the pregnancy is progressing. Serial measurements help confirm that the embryo is developing appropriately.

⚠️ Detect Potential Issues

Unusually low levels or slow doubling time may suggest miscarriage, ectopic pregnancy, or other concerns that require medical attention.

👶 Identify Multiple Pregnancies

Higher-than-expected HCG levels may indicate twins, triplets, or more. However, ultrasound is needed to confirm multiples.

📋 Guide Clinical Decisions

HCG trends help healthcare providers decide on the timing of ultrasounds and whether additional testing or intervention is needed.

Frequently Asked Questions

What is a normal HCG level at 4 weeks pregnant?

At 4 weeks pregnant, a normal HCG level typically ranges from 5 to 426 mIU/mL. However, HCG levels vary significantly between individuals. The most important factor is not the absolute number but whether the level is rising appropriately over time. A single reading within this range is generally reassuring, but your healthcare provider will consider the full clinical picture.

What does it mean if my HCG is low?

If your HCG level is below the reference range for your week of pregnancy, it could indicate a very early pregnancy (dating may be off), a possible miscarriage, or an ectopic pregnancy where the embryo implants outside the uterus. A single low reading is not diagnostic — your provider will likely repeat the test in 48–72 hours to see the trend. Low HCG levels that are still rising appropriately may be less concerning than levels that are rising slowly or falling.

What HCG doubling time is considered normal?

In early pregnancy (up to about 6–8 weeks), HCG levels typically double every 48–72 hours. A doubling time under 72 hours is generally considered normal and reassuring. As pregnancy progresses beyond 8 weeks, the doubling time naturally slows down and may exceed 96 hours. After HCG peaks around 8–10 weeks, levels actually decline. A doubling time shorter than 48 hours can occur with multiple pregnancies or certain medical conditions. Always discuss your results with a healthcare provider.

Can HCG levels vary between different women at the same stage?

Absolutely. HCG levels vary enormously between different women at the same week of pregnancy. For example, at 5 weeks, one woman might have an HCG level of 50 mIU/mL while another has 4,000 mIU/mL — both within the normal range of 18–7,340 mIU/mL. This wide variability is why healthcare providers focus on the trend over time rather than comparing absolute values with other women. What matters most is that your levels are rising appropriately for your own pregnancy.

Does a high HCG level mean I'm having twins?

Higher HCG levels can be associated with multiple pregnancies (twins, triplets), but they are not definitive proof. Many women with singleton pregnancies also have HCG levels on the higher end of the reference range. Conversely, some women with twins have HCG levels that fall within the normal singleton range. Ultrasound is the only reliable way to confirm a multiple pregnancy. Other causes of high HCG include molar pregnancy or inaccurate pregnancy dating.

When should I stop tracking HCG levels?

Most healthcare providers stop monitoring HCG levels once an ultrasound confirms a viable pregnancy with a visible fetal heartbeat, typically around 6–8 weeks. After this point, HCG levels rise more slowly and eventually plateau and decline. Ultrasound provides more reliable information about fetal development than HCG trends. If you have a history of miscarriage or other risk factors, your provider may continue monitoring HCG for longer, but this is determined on a case-by-case basis.

⚠️ Important Medical Disclaimer: This HCG Levels Calculator is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. HCG levels vary widely between individuals and pregnancies. Always consult a qualified healthcare provider with any questions about your HCG levels or pregnancy health. Do not make medical decisions based solely on the results from this calculator.