UZI TOOLS

Ovulation & Fertility Calculator

Predict your fertile window and ovulation date from your cycle length and last period.

Ovulation & Fertility Calculator calculator

Enter the first day of your last period and your average cycle length (days). Ovulation is estimated at about 14 days before your next period; the fertile window is the 5 days before ovulation plus the day of ovulation.

Estimated ovulation: Sat, Feb 15

Fertile window: Mon, Feb 10 - Sun, Feb 16

Next period (est.): Sat, Mar 1

How To Use

  1. Enter the first day of your last period.
  2. Enter your average cycle length in days (e.g. 28).
  3. Review estimated ovulation date and fertile window (5 days before ovulation through day of ovulation).

What Is Ovulation & Fertility?

An ovulation calculator estimates when you are likely to ovulate and your fertile window—the days when conception is most likely. Ovulation typically occurs about 14 days before your next period; the fertile window is usually the 5 days before ovulation plus the day of ovulation, since sperm can live several days and the egg about 24 hours. This tool uses your last period date and average cycle length for the estimate. It is for education only; for conception or cycle concerns, consult a healthcare provider.

Frequently Asked Questions

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