Ovulation Calculator

Estimate your likely ovulation date, fertile window, next period, and suggested pregnancy test timing based on the first day of your last period and your average cycle length.

Cycle Inputs
Use your typical cycle length if you know it. Results are estimates, not guarantees.
Fertility Timeline
The fertile window begins several days before ovulation because sperm can survive in the reproductive tract.
Likely ovulation date
Thursday, March 19, 2026
Fertile window
Mar 14 to Mar 20
Estimated next period
Thursday, April 2, 2026
Suggested test date
Sunday, March 29, 2026
Use the fertile window as planning guidance only. Irregular cycles can shift ovulation earlier or later.
Why the fertile window starts early
Pregnancy is possible before the exact day of ovulation.

Sperm can survive for up to five days in fertile cervical mucus, while the egg is available for only a short time after ovulation. That is why the highest-probability window starts several days before the projected ovulation date.

If your cycle varies a lot from month to month, ovulation test strips or cycle tracking with a clinician may give you better precision.

Frequently Asked Questions

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