hCG Doubling-Time Calculator
Calculate the mathematical change between two quantitative hCG blood test results. hCG does not need to literally double every 48 hours.
Your mathematical results will appear here.
- Elapsed time
- Total change
- Estimated 48-hour change
(log-linear)
The 48-hour estimate assumes log-linear change between the two test times. Clinicians commonly interpret serial results drawn around 48 hours apart, together with symptoms and ultrasound.
The calculator intentionally does not label a result normal, abnormal, viable, or nonviable.
hCG values cannot diagnose pregnancy location or outcome by themselves. Seek emergency medical care now for severe or one-sided abdominal or pelvic pain, shoulder-tip pain, fainting, dizziness, or significant bleeding, or if symptoms are new or worsening.
A clinician must interpret serial hCG results with symptoms, ultrasound findings, gestational timing, and the laboratory method.