Beta HCG by Week Calculator – Expected Hormone Ranges
Find expected HCG levels by week of pregnancy
This calculator provides reference ranges for educational purposes only. HCG levels vary significantly between individuals and normal pregnancies. A single HCG value does not confirm or rule out pregnancy viability. Always consult with your healthcare provider for proper interpretation of lab results.
Table of Contents
How to Use
- Enter your weeks of pregnancy (3-40 weeks)
- Weeks are calculated from Last Menstrual Period (LMP)
- Click calculate to see expected HCG range
- Compare your actual HCG level with the normal range
HCG Levels by Week of Pregnancy
Beta HCG levels rise rapidly in early pregnancy, typically doubling every 48-72 hours during the first 8-10 weeks. Levels peak between 8-11 weeks of pregnancy before declining and leveling off for the remainder of pregnancy.
| Gestational Age | HCG Range (mIU/mL) | Doubling Time |
|---|---|---|
| 3 weeks | 5 - 50 | 48-72 hours |
| 4 weeks | 5 - 426 | 48-72 hours |
| 5 weeks | 18 - 7,340 | 48-72 hours |
| 6 weeks | 1,080 - 56,500 | 72-96 hours |
| 7-8 weeks | 7,650 - 229,000 | 72-96 hours |
| 9-12 weeks | 25,700 - 288,000 | 96+ hours |
| 13-16 weeks | 13,300 - 254,000 | Plateau |
| 17-24 weeks | 4,060 - 165,400 | Plateau |
| 25-40 weeks | 3,640 - 117,000 | Plateau |
Understanding HCG Ranges
The wide ranges in HCG levels reflect normal individual variation. A value at the lower end of the range can be completely normal for some pregnancies, just as a value at the higher end can be normal for others.
- Timing of implantation affects initial HCG levels
- Multiple gestations (twins, triplets) have higher HCG levels
- Calculation errors in gestational age are common
- Laboratory measurement methods vary between facilities
- The trend over time is more important than a single value
- Rising HCG that doesn't double may indicate problems
- Declining HCG levels may indicate miscarriage
When to Test HCG Levels
Blood HCG testing is typically ordered by healthcare providers in specific situations:
- To confirm pregnancy when home tests are unclear
- To date early pregnancy before ultrasound can visualize gestational sac
- To monitor early pregnancy when there are concerns
- To investigate suspected ectopic pregnancy
- To assess for possible miscarriage
- To monitor after miscarriage or pregnancy loss
- To screen for molar pregnancy or gestational trophoblastic disease
Significance of Doubling Time
In viable pregnancies, HCG levels should roughly double every 48-72 hours in early pregnancy. Serial measurements taken 2-3 days apart can help assess pregnancy viability:
- Normal doubling: HCG increases by at least 66% in 48 hours
- Slow rise: May indicate ectopic pregnancy or impending miscarriage
- Declining levels: Typically indicates pregnancy loss
- Extremely high levels: May indicate molar pregnancy or multiple gestation
- After 6 weeks: Doubling time slows down naturally
- After 10-12 weeks: HCG levels plateau and may decline
Frequently Asked Questions
- What is a normal HCG level for my week of pregnancy?
- Normal HCG ranges are extremely wide and vary by individual. Use this calculator to find the typical range for your week, but remember that being at the low or high end of the range can be completely normal.
- Should my HCG be doubling every 48 hours?
- In early pregnancy (weeks 3-6), HCG typically doubles every 48-72 hours. After 6 weeks, the doubling time slows to 72-96 hours or longer. After 10-12 weeks, HCG levels plateau.
- Can high HCG levels mean twins?
- Twin pregnancies often have higher HCG levels than singleton pregnancies, but there's significant overlap in ranges. Ultrasound is the only definitive way to confirm multiple gestation.
- What if my HCG is lower than the range?
- Low HCG doesn't automatically mean a problem. It may indicate earlier pregnancy than calculated, later implantation, or individual variation. Your provider will typically order repeat testing to assess the trend.
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