MyMonthlyCycles Menstrual Calculator

Women everywhere, forever, and for many good reasons need or want to predict when their period is coming.

That used to mean pulling out the paper calendar and the calculator, averaging menstrual cycle length by hand, etc. Say goodbye to all that!

Based on your menstrual tracking history, MyMonthlyCycles can forecast your forthcoming menstruation dates, up to 18 months in advance.

Just want to play what-if? Easy, too, with the Quick Calculate option.

Update: Since releasing our period calculator in 2003, we've added dozens of menstrual cycle calculators, fertility calculators, and pregnancy calculators.