Track your fertile window, ovulation day, and upcoming periods
Ovulation typically occurs 12–16 days before your next period. Sperm can survive for up to 5 days in the reproductive tract, making the 5 days before ovulation plus ovulation day itself the peak fertility window.
The luteal phase (time between ovulation and next period) is fairly constant at 12–14 days for most women. If you have irregular cycles, tracking your basal body temperature or using ovulation test strips will give more accurate results.
This calculator is for informational and family planning purposes only. It is not a reliable method of contraception. Consult your doctor for medical advice.