buncha/time & productivity/ovulation

Ovulation Calculator

For awareness only. This calculator predicts based on cycle averages. It is not reliable contraception and not a substitute for medical advice. Cycles vary — fertile windows can shift.

First day of last period

Cycle length28 days

From day 1 of one period to day 1 of next

Period length5 days

How long bleeding typically lasts

Ovulation typically occurs 14 days before your next period. Fertile window is the 5 days before plus the day of ovulation.

Read the guide

BBT Charting Basics — How the Thermal Shift Confirms Ovulation

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About Ovulation Calculator

Track your menstrual cycle, predict fertile window and ovulation. Free online ovulation tracker.

Like every tool on Buncha, this one runs entirely in your browser. There's no upload, no log, no record of what you've pasted or generated. Close the tab and the data is gone.

↳ Have feedback or found a bug? hello@buncha.tools