Calculate your ovulation date, fertile window, and peak fertility days.
The date estimate is calculated from the entered cycle, last menstrual period, conception date or gestational reference using standard calendar intervals.The estimate applies standard calendar intervals to the selected last-period, conception, due-date or cycle information. Irregular cycles, assisted reproduction, ultrasound dating and clinical findings can change the relevant date.
Ovulation Calculator estimates a pregnancy, gestational or fertility-related date from the cycle or reference date entered. Calculate your ovulation date, fertile window, and peak fertility days. It provides a calendar estimate, not confirmation of conception, gestational age or delivery timing.
It is an estimate generated from the values entered on this page and the calculation method shown in the formula and methodology sections.
The calculator validates the entered values, applies the protected formula shown on the page and then rounds only the displayed result where appropriate.
Use current source values, confirm units and time periods, include every requested cost or measurement, and avoid rounding inputs before the final calculation.
Different calculators may use different assumptions, time periods, rounding rules, reference standards or included costs. Compare the inputs and limitations before comparing answers.
No. It is an educational estimate and cannot account for every medical history, medication, measurement issue or individual biological factor.
Recalculate whenever a material input changes, such as a rate, price, balance, measurement, time period, fee, contribution or project dimension.
Enter the best available date and the cycle information requested. Use the output for planning, then rely on clinical assessment for medical decisions and official pregnancy dating.