CalcMate

Ovulation Calculator

Find your most fertile days and next estimated ovulation date based on your last period and cycle length.

About the Ovulation Calculator

Ovulation happens about 14 days before the next period, not a fixed time after the last one. Since sperm survive up to five days, the fertile window spans roughly ovulation minus 5 days to ovulation plus 1 day.

Informational only, not medical advice.