📆 Ovulation Calculator
Estimate your ovulation date and fertile window from the first day of your last period and your average cycle length. For general information only; not medical advice, a diagnosis, or birth control.
This is an estimate-only ovulation tool built on fixed assumptions for relatively regular cycles. It is only intended as general information for cycles that are usually 21 to 35 days long, and it is less reliable for irregular cycles.
Results on this page are not medical advice or a diagnosis. They must not be used for birth control or as a substitute for a clinician or midwife.
Privacy note: Calculations run locally by default. Your date and cycle inputs are not uploaded.
Disclaimer: This page only provides an estimate and general information. It is not medical advice, a diagnosis, or an individualized assessment, and it must not be used for birth control.
This kind of fixed-date estimate is usually less reliable when cycles are irregular or when other factors affect ovulation timing.
Privacy note: Calculations run locally by default. Your date and cycle inputs are not uploaded.
Estimate ovulation date, fertile window, and ovulation cycle day from the first day of the last period and an average cycle length. The result is a timeline reference for usually regular cycles, not a substitute for ovulation tests, basal temperature tracking, clinical advice, or irregular-cycle evaluation. It is not medical advice, a diagnosis, or birth control.