Ovulation Calculator

Estimate the likely ovulation date and fertile window based on the first day of your last period and your average menstrual cycle length.

Inputs
Results
Estimated Ovulation Date
2026-07-15
Fertile Window Start
2026-07-10
Fertile Window End
2026-07-16

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Formula

Ovulation ≈ Cycle Length − 14 days after period start

Learn How This Works

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Frequently Asked Questions

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