Ovulation Test Calculator

Find your ovulation day, fertile window, and the best day to start ovulation predictor kits (OPKs).

Privacy: All data is calculated locally in your browser. No personal data is stored or sent to any server.

Your cycle details

The first day of full flow (Day 1 of your cycle).

Typical range: 21–35 days. Allowed: 21–45.

Fertility tips