Fertility Ovulation Calculator

Estimate your fertile window and ovulation days.

Enter your last period date, cycle details, and optional basal temperature, mucus, or OPK data to estimate ovulation and fertile days.

This tool is for general information only and does not replace medical advice. All calculations run on your device.

Ovulation overview

Estimated ovulation

Method:-

Fertile window

Expected next period

Cycle details

First day of last period

Average cycle length (days)

Period length (days)

Luteal phase length (days)

Optional recent cycle lengths (days)

Separate numbers with spaces, commas, or new lines.

Optional fertility signs

Basal temperature values in Celsius

Use at least 9 values for a temperature based estimate.

First positive OPK test (optional)

Recent cervical mucus

Stretchy or egg white like mucus appears near ovulation.

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