Predict upcoming periods and fertile windows based on your cycle.
This period calculator predicts your upcoming menstrual periods, fertile windows, and estimated ovulation dates based on the first day of your last period and your average cycle length. It forecasts up to 12 cycles ahead so you can plan vacations, events, or fertility tracking with confidence.
Multi-Cycle Forecast
See up to 12 upcoming cycles at once with period, fertile window, and ovulation dates.
Customisable Cycle
Adjust cycle length (20–45 days) and period length (1–10 days) to match your personal pattern.
Fertile Window & Ovulation
Each cycle highlights the 6-day fertile window and estimated ovulation day.
100% Private
Nothing leaves your browser — no accounts, no tracking, no data collection.
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