HCG Level Doubling Time Calculator

In a healthy early pregnancy, hCG typically doubles every 48-72 hours until it reaches about 1,200 mIU/mL. From 1,200-6,000, doubling slows to every 72-96 hours. Above 6,000, it doubles every 96+ hours. hCG peaks around 8-11 weeks, then gradually declines.

A slower-than-expected hCG rise can indicate: ectopic pregnancy, miscarriage, or simply normal variation (not all healthy pregnancies follow the '48-hour doubling' rule). About 15% of normal pregnancies have slower initial hCG rise. Your provider will evaluate the complete clinical picture.

Higher-than-average hCG levels or very fast doubling times can sometimes indicate twins or multiples, but this is not a reliable indicator. Many twin pregnancies have normal hCG levels, and some singleton pregnancies have high levels. Ultrasound is the only reliable way to confirm multiples.