Ovulation Calculator

Find your fertile window and best days to conceive based on your cycle.

First day of your last period

Average cycle length (days)

Most cycles run between 21 and 35 days. If unsure, use 28.

Fertile Window

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Estimated Ovulation Day

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Next Expected Period

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This tool gives an estimate only and isn't a substitute for medical advice. Ovulation timing can vary cycle to cycle.