Ovulation Calculator
Estimate your next ovulation date and fertile window from your cycle.
Ovulation typically occurs about 14 days before your next period starts, regardless of your total cycle length — which is why cycle length, not a fixed calendar date, determines your estimated fertile window.
Why cycle length matters more than a fixed day
A common misconception is that ovulation always happens on "day 14" — that's only true for an exact 28-day cycle. For a 32-day cycle, ovulation is estimated around day 18. This calculator adjusts automatically based on your actual average cycle length.
Frequently asked questions
How accurate is this estimate?
It's a useful starting estimate, but ovulation predictor kits or tracking basal body temperature give more precise, personalized data.
What if my cycle length varies month to month?
Use your average cycle length over the past several months for the most reasonable estimate.