Ovulation Calculator
Track your most fertile days and predict your next period. Increase your chances of getting pregnant by calculating your ovulation window based on your cycle.
Most cycles range from 21 to 35 days.
Understanding Your Fertile Window
Ovulation is the release of a mature egg from the ovary. It typically happens once every menstrual cycle, about 14 days before your next period starts.
However, you are fertile for more than just 24 hours. Sperm can survive inside the female body for up to 5 days. This creates a "fertile window" of about 6 days:
- 5 Days Before Ovulation: Intercourse during these days allows sperm to wait for the egg.
- Ovulation Day: The peak of fertility. The egg survives for 12-24 hours after release.
- 1 Day After: The window closes rapidly as the egg dissolves if not fertilized.
How Cycle Length Affects Ovulation
A "standard" cycle is 28 days, with ovulation on day 14. But many women vary:
- Short Cycle (21 days): Ovulation likely occurs around day 7.
- Long Cycle (35 days): Ovulation likely occurs around day 21.
This calculator adjusts based on your input. If your cycle is irregular, the results may be less accurate. In that case, look for physical signs of ovulation (like changes in cervical mucus or basal body temperature).
Trying to conceive? Once you get a positive test, use our Due Date Calculator to find out when your baby will arrive!
? Frequently Asked Questions
It is extremely unlikely. For pregnancy to occur, a viable egg and sperm must meet. Once the egg dissolves (12-24 hours after ovulation), conception is not possible until the next cycle.
This calculator relies on averages. If your cycle varies by more than a few days each month, these dates are estimates. Consider using ovulation predictor kits (OPKs) for better precision.
For most women, the luteal phase (time from ovulation to period) is consistently 12-16 days (average 14). The first part of the cycle (follicular phase) is what usually varies in length.
The process of releasing the egg is instantaneous, but the egg survives for 12 to 24 hours. The 'fertile window' is longer (approx 6 days) because of sperm survival time.