Home › Calculators › Ovulation Calculator
Free calculatorOvulation Calculator
Find the day you are most likely to ovulate — plus your fertile window and the next three cycles — from your last period and cycle length.
Frequently asked questions
When do I ovulate?
Ovulation usually happens about 14 days before your next period. For a 28-day cycle that is around day 14; for a 30-day cycle, around day 16.
How does the ovulation calculator work?
It subtracts 14 days from your expected next period (last period + cycle length) to estimate ovulation, then shows the fertile window around it.
Related
Note: These calculators give estimates for general guidance only and are not a substitute for medical advice. Your doctor confirms your dates and due date by ultrasound.