Period Calculator
Estimate the next period, period end, and fertile window from cycle history.
Next period estimate
November 9, 2026
based on a 28-day cycle
Estimated next period endsNovember 13, 2026
Estimated ovulationOctober 26, 2026
Estimated fertile windowOct 21, 26 – Oct 27, 26
Cycle predictions are estimates; cycles naturally vary. This is not a contraceptive method. Estimates for general guidance only — not medical advice. Check with a qualified healthcare professional for personal decisions.
About the Period Calculator
Estimate the next period, period end, and fertile window from cycle history.
It runs entirely in your browser — nothing you type is sent to a server — and the result updates as you edit the inputs. Estimates are for educational and informational purposes only; see ourdisclaimer.
Common searches
- menstrual cycle
- next period
- fertile
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