Ovulation calculator

Find the fertile window, then track the signals that confirm it.

What it does

The ovulation calculator estimates your ovulation date and fertile window from the first day of your last period and your average cycle length, with a luteal-phase adjustment for finer timing. It goes beyond the estimate: a Daily BBT & Symptom Tracker logs basal body temperature, LH test strip results, cervical mucus, and symptoms in your browser; there is live partner sync by link or QR code, and a printable Ovulation & Fertile Window Summary Report. The tool is explicit that calendar prediction is educational planning only, not medical advice.

Who it’s for

Anyone trying to conceive who wants the calendar estimate and the daily signal-tracking in one place — and a report they can bring to an appointment.

How to use it, step by step

Enter the first day of your last period and your average cycle length; adjust the luteal phase if you know yours.
Tap Calculate to see your estimated ovulation date and fertile window.
Each day, open the BBT & Symptom Log and record temperature, LH strip result, cervical mucus, and any symptoms.
Share the live sync link or QR code with your partner so you are both looking at the same window.
Print the Clinical Fertility Report tab to take your cycle history to your provider.

What you get

An estimated ovulation date and fertile window, a growing daily BBT/symptom log, and a printable fertility summary report.

✦ A worked example

You give it

Last period started on the 1st, average cycle 28 days.

You get

An estimated ovulation around day 14 with the fertile window shaded in the days just before it — then a BBT entry of 97.8 with an "Egg White (Fertile)" mucus note logged for that morning.

💡 Tips & tricks

The luteal-phase slider matters: if yours is shorter or longer than the standard 14 days, the ovulation estimate shifts to match.
Log LH strips alongside BBT — a positive strip plus a temperature rise is the classic one-two confirmation.

Enough reading — the tool itself is one tap away, and it is free.

Try the Ovulation calculator →

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