Ovulation Calendar Calculator

An ovulation calendar predicts future ovulation dates based on your cycle length. Ovulation typically occurs 14 days before your next period (the luteal phase). For a 28-day cycle, that's day 14. For a 30-day cycle, day 16.

Yes. Tracking 3-6 months of cycle data reveals patterns and helps identify if your cycles are regular. Most women have some variation (± 1-3 days), which is perfectly normal and helps refine predictions.

The calendar/rhythm method alone is only about 76-88% effective as contraception. It doesn't account for cycle irregularities, stress, illness, or other factors that can shift ovulation. More reliable methods are recommended.