Ovulation Calculator
Find your fertile window and predicted ovulation date. Based on your last period and cycle length.
Predicted Ovulation Date
This is an estimate. Actual ovulation varies. Consider using an ovulation predictor kit (OPK) for confirmation.
📐 Formula
Ovulation Day = LMP + (Cycle Length − 14). Fertile Window = Ovulation Day −5 to +1
Frequently Asked Questions
Most women ovulate 14 days before their next period starts — not necessarily 14 days after their last period. If your cycle is 30 days, you likely ovulate on day 16. This calculator adjusts for your cycle length.
The fertile window is typically 6 days — the 5 days before ovulation and ovulation day itself. Sperm can survive in the reproductive tract for up to 5 days, so intercourse before ovulation can still result in pregnancy.
No. This calculator should NOT be used as contraception. Cycle length varies month to month, and this method has a high failure rate. Consult a healthcare provider for reliable contraceptive advice.