Cycle length calculator

Find your average and most common cycle lengths

Enter the first day of your last few menstrual periods to view your shortest and longest cycles and to calculate your average cycle length and most common cycle length. The more dates you enter the more accurate the results will be.

Once you have your average cycle length you can use this number in the:

 

Enter cycle start dates

A cycle start date is the first day of your period.

        

        

        

        

        

        

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