Ovulation Calculator
Estimate your most fertile days based on your menstrual cycle. This calculator helps predict ovulation timing for family planning purposes.
Most cycles are 21-35 days. Average is 28 days.
Enter your cycle information to see your fertile window.
How It Works
Ovulation typically occurs about 14 days before your next period begins. The fertile window spans roughly 5 days before ovulation through the day after, as sperm can survive up to 5 days and the egg is viable for about 24 hours after release.
This calculator uses the calendar method, which works best for those with regular cycles. For irregular cycles or more precise tracking, consider additional methods like ovulation predictor kits (OPKs), basal body temperature charting, or cervical mucus monitoring.
Frequently Asked Questions
How accurate is this calculator?
Calendar-based predictions are estimates. Even with regular cycles, ovulation can vary by several days. For conception planning, combine this with other tracking methods. This calculator should not be used as contraception.
What affects ovulation timing?
Stress, illness, travel, weight changes, and hormonal imbalances can all affect when you ovulate. Even women with regular cycles can occasionally ovulate earlier or later than expected.
What are signs of ovulation?
Common signs include changes in cervical mucus (becoming clear and stretchy), mild pelvic pain (mittelschmerz), increased libido, breast tenderness, and a slight rise in basal body temperature after ovulation.
When should I take a pregnancy test?
For best accuracy, wait until the first day of your missed period. Testing too early may give a false negative. If you get a negative result but your period doesn't come, wait a few days and test again.