Free Menstrual Cycle Length Calculator

Use this calculator to calculate your shortest, longest, and average menstrual cycle length. Enter just the first day of your last several periods and click calculate to see your menstrual cycle chart.

Today's Date (Jul 4 2008)

Period start date:

How to calculate average menstrual cycle length...

Use MyMonthlyCycles.com FREE Period Tracking Calendar! Opens in new window

and your cycle statistics are auto-calculated as you track!

Setup your free account at MyMonthlyCycles.
Use the Period Calendar. Click your period dates. Track as many past periods as you want!
Each time you track your period, your cycle statistics are re-calculated!
Use My History (Quick History) for your cycle summary.
Transport your cycle stats to WhenMyBaby! Click the WhenMyBaby link on MyMonthlyCycles for details.

Free tools for your cycles at MyMonthlyCycles.com Opens in new window