Ovulation Calculator

Estimate when you're most likely to ovulate based on your last period and cycle length. Shows your fertile window - the days when conception is most likely.

Medical note
Ovulation timing varies person to person. This estimate assumes ovulation ~14 days before the next period. Use it for planning only.
Jun 21, 2026
Ovulation (est.)
Jun 16, 2026 – Jun 22, 2026
Fertile window
Jul 5, 2026
Next period (est.)
Next cycles (est.)
Cycle 2
Ovulation: Jul 19, 2026
Fertile: Jul 14, 2026Jul 20, 2026
Period: Jul 5, 2026
Cycle 3
Ovulation: Aug 16, 2026
Fertile: Aug 11, 2026Aug 17, 2026
Period: Aug 2, 2026
Cycle 4
Ovulation: Sep 13, 2026
Fertile: Sep 8, 2026Sep 14, 2026
Period: Aug 30, 2026

How to use

  1. Enter the first day of your last period.
  2. Enter your usual cycle length. If it varies, use your average.
  3. You'll see your estimated ovulation date and the fertile window around it.