Period Calculator

Next period dates from last period and cycle length.

Last period (first day)Cycle length (days)

Next period

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Expected end

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Period after that

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How to estimate your next period free

Calculate Next Period free with this period calculator. It estimates next period dates from last period and cycle length.

How to estimate your next period: enter the first day of your last period and cycle length.

This period calculator free page is built for desktop and mobile. Period Calculator Online free means no account, no install, and no signup.

How do I estimate my next period?

Enter the first day of your last period and cycle length. Estimated next period dates appear on the right.

Does irregular cycling change the result?

Yes. The estimate assumes a regular cycle length. Irregular cycles need a clinician for tracking, not this planning aid alone.

Is the period calculator free?

Yes. You can calculate next period free with no signup and no software to install.

Can I calculate next period on mobile?

Yes. This period calculator online free tool works in a mobile browser. Open the page and get your result.

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