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Calculators

Fertile Window Calculator

Estimate the next period, ovulation day and six-day fertile window from cycle dates.

On your deviceFREENo account needed

Guest results are not saved to an account. Sign in before processing to keep results in your private history for 30 days.

ExampleSee sample input and settings

Load the example, adjust the values, then run the tool.

Last period start
Today
Cycle length
28
Luteal phase length
14

Loading…

About this tool

Estimate the next period, ovulation day and six-day fertile window from cycle dates.

Choose your options, process your input, and download or copy the result.

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