Free calculator

Beta hCG doubling time

Calculate hCG doubling time from two quantitative lab results and see a simple chart of the trend.

Estimate, not a diagnosis. This tool gives an educational estimate based on the numbers you enter. It cannot account for your individual health history — consult a healthcare professional for anything clinical.

First reading

Date 1

July 2026

SMTWTFS

hCG value 1 (mIU/mL)

Second reading

Date 2

July 2026

SMTWTFS

hCG value 2 (mIU/mL)

How this works

Using two hCG values and their dates, we estimate the exponential growth rate and report the doubling time in days. Early pregnancy typically shows roughly doubling every 48–72 hours, but values vary.

Limitations

Assay differences, lab error, and biological variation affect results. This is an aid, not a diagnosis — discuss abnormal patterns with your clinician.