hCG Doubling Time Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026
Disclaimer: This calculator is provided for informational and educational purposes only and does not constitute financial, medical, legal, or other professional advice. Always consult a qualified professional before making decisions based on these results.
What hCG doubling patterns can suggest
In a normal early intrauterine pregnancy, hCG levels typically double roughly every 48-72 hours - tracking this doubling pattern across two blood tests is a standard early pregnancy assessment tool.
Worked example
For hCG rising from 100 to 200 mIU/mL over 60 hours:
Doubling Time = (60 x ln(2)) / ln(200/100) = 60.0 hours (Within commonly cited normal range)
Significantly slower doubling than the expected 48-72 hour range can raise concern for early pregnancy loss or ectopic pregnancy, though hCG patterns alone are never diagnostic on their own and always require clinical correlation with ultrasound findings and symptoms.
This is an informational tool only, not a substitute for evaluation and follow-up by a qualified healthcare provider.