hCG Doubling Time Calculator
Use this hcg doubling time calculator to estimate the time between two hCG blood test results. Enter the first hCG value, second value and time between tests and review an estimated hCG doubling time and rate of change.
Informational only — hCG trends must be interpreted by your healthcare provider alongside ultrasound.
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How it works
Doubling time = hours between tests × ln(2) ÷ ln(hCG₂ ÷ hCG₁)How to use the hCG Doubling Time Calculator
Start by entering the first hCG value, second value and time between tests. Keep the units consistent and check that each value belongs to the same question.
The result gives an estimated hCG doubling time and rate of change. One result cannot diagnose a pregnancy outcome and laboratory results need clinical interpretation. Use it as a guide and check any instructions, rules or professional advice that apply.