Ovulation Calculator
Fertility Tracker
Results
| Next Ovulation Date | — |
|---|---|
| Next Fertile Window | — |
| Pregnancy Test Date | — |
How Ovulation & Fertility Windows are Calculated
Ovulation is the release of a mature egg from the ovary. Fertilization must occur within 12 to 24 hours after the egg is released. However, because sperm can survive up to 5 days, your "fertile window" starts 5 days before ovulation and ends on the day of ovulation.
Calculating the Dates
- Ovulation Date: Ovulation occurs about 14 days before the start of the next menstrual period. This is based on the luteal phase length, which is the time between ovulation and the next period. Formula: $\text{Ovulation Date} = \text{First day of last period} + \text{Cycle Length} - \text{Luteal Phase}$.
- Fertile Window: The window spans 6 days: the day of ovulation and the 5 preceding days. Intercourse during this window yields the highest probability of conception.
- Pregnancy Test Date: A standard home pregnancy test detects human chorionic gonadotropin (hCG) in urine. This is typically accurate beginning 14 days after ovulation.
Disclaimer. This calculator predicts statistical windows based on input variables. Cycle regularity varies, and biological factors can shift ovulation dates. This tool is not intended for contraceptive purposes or medical diagnosis.