hCG Doubling Calculator — Beta hCG Doubling Time
Calculators
4.6
Active
Updated Apr 8
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– hours
doubling time · – days · –% rise over –h
–
Educational use only — this is not medical advice.
hCG patterns vary widely between pregnancies, and a single doubling-time number cannot diagnose a healthy or unhealthy pregnancy. Beta-hCG interpretation depends on your clinical history, gestational age, and other factors that only your doctor or midwife can assess. If you are worried about your lab results, contact your healthcare provider — do not make medical decisions based on this calculator. All calculations happen in your browser; no data is uploaded or stored.
How does the hCG doubling time calculator work?
Enter two beta-hCG (quantitative "beta") blood test results with their exact draw dates and times. The calculator finds the hours between the two draws and applies the standard exponential-growth formula:
Doubling time = elapsed hours × log(2) ÷ log(v2 ÷ v1)
- Typical range: in early pregnancy, hCG often doubles roughly every 48–72 hours. A slower rise (e.g. 3–4+ days) can still be completely normal, especially at higher hCG levels where doubling naturally slows.
- Not a verdict: hCG doubling time alone does not determine viability. Clinicians look at the whole picture — ultrasound findings, symptoms, and trends across multiple draws.
- Inputs required: the second value must be higher than the first, both must be positive numbers, and the second draw must be dated after the first.
- Private: your lab values never leave your device; the math runs entirely in your browser.
When in doubt, always ask the clinician who ordered your labs — they know your full clinical context.
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Tool Information
Category
Calculators
Updated
Apr 8
Status
Active
Rating
4.6
Type
Free Tool
159 people used this tool
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