Ovulation Calculator

Find your 5-day fertile window using your cycle data — backed by clinical algorithms.

50,000+ women
Clinic-backed

Your results will appear here

Fill in your LMP and cycle length on the left, then tap Calculate.

Ovulation date — waiting for your data
Fertile window — waiting for your data
Next period — waiting for your data
Cycle day map — waiting for your data

👉 Success Tip: Tracking your LH surge with an ovulation kit is the most accurate way to confirm the fertile window our calculator has estimated for you.

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Understanding Your Ovulation

The Fertile Window

Your fertile window includes the 5 days before ovulation and the day of ovulation. Sperm can survive up to 5 days inside the reproductive tract, waiting for the egg to be released.

Accuracy Factors

Calendar-based calculators are most accurate for regular cycles. If your cycle varies by more than 3 days, we recommend tracking basal body temperature or cervical mucus changes.

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