Accurate Ovulation Calculator
Use this free accurate ovulation calculator to estimate ovulation day, fertile window and next period from cycle length.
Health information notice: Results are estimates based on general formulas and may not reflect individual circumstances. This tool is not a diagnosis or substitute for personalized advice from a qualified healthcare professional.
How the accurate ovulation calculator works
Ovulation is estimated at cycle length minus the luteal phase (usually 14 days). The fertile window is the 5 days before ovulation through 1 day after.
Frequently asked questions
Is this exact?
No. Ovulation varies; ovulation tests or tracking temperature can help. It is not a contraceptive method.
Results are estimates for general information only. They are not a substitute for professional advice where applicable. Found a mistake? Report an error.