Ovulation Calculator
Estimate your ovulation date and fertile window.
Frequently Asked Questions
How is the ovulation date calculated from cycle length? +
Ovulation typically occurs 14 days before the start of your next period, not 14 days after your last one. So for a 28-day cycle, ovulation is around day 14. For a 32-day cycle, it would be around day 18 (32 - 14 = 18).
How long is the fertile window each cycle? +
The fertile window spans about 6 days: the 5 days before ovulation plus ovulation day itself. Sperm can survive in the reproductive tract for up to 5 days, while the egg is viable for 12-24 hours after release.
What if my cycle length varies from month to month? +
Use your average cycle length over the past 3-6 months for the best estimate. If your cycles vary by more than a week, ovulation prediction becomes less reliable. Tracking basal body temperature or using ovulation test strips can provide more accurate timing.
Can I use this calculator as a contraceptive method? +
No. Ovulation calculators provide estimates only and should not be relied upon to prevent pregnancy. Cycle timing can shift due to stress, illness, travel, and other factors. Consult a healthcare provider for reliable contraception options.