About hCGCalculator.com
Who builds this, how every number is verified, and why there are no ads.
hCGCalculator.com takes the single most anxiety-producing number in early pregnancy — hCG — and surrounds it with honest, verified evidence. The calculator computes doubling time and the projected 48-hour rise, then evaluates it against every major published threshold — not just one. Where guidelines disagree (as the US evidence and the UK's NICE guideline sometimes do), we show the disagreement openly rather than papering over it.
Amos Grünebaum, MD is a Professor of Obstetrics and Gynecology and a specialist in Maternal-Fetal Medicine with over 50 years of clinical experience caring for pregnant patients. He has authored hundreds of peer-reviewed publications on pregnancy and childbirth and publishes ObGyn Intelligence — The Evidence of Women's Health at obmd.com.
hCGCalculator.com is part of the ObGyn Intelligence family of free, evidence-based clinical calculators and patient education tools (tools.obmd.com), built on one principle: every number must be traceable to verified evidence, and uncertainty must be reported honestly.
The calculator includes a clinician mode with the full threshold provenance (Barnhart 2016 first-percentile stratified minimums, Barnhart 2004, Seeber/Morse floor, NICE NG126) and a copyable chart note. The content pages pair patient-level explanations with the primary literature. Corrections and suggestions are welcome via obmd.com.