Ovulation Calculator

We estimate your next period from your last period and average cycle length, then subtract 14 days. This is a fixed calendar assumption: actual ovulation timing varies. The result does not confirm that an egg has been released.

A calendar alone cannot pinpoint ovulation. The NHS explains that ovulation commonly happens around 10–16 days before the next period. Treat the highlighted day as a guide, not an exact date.

The tool accepts cycles of 21–35 days and repeats one average length. Do not substitute a different length if yours falls outside this range. Irregular cycles, hormonal contraception, and changes after pregnancy can make calendar predictions unreliable. Even regular cycles do not guarantee ovulation on the predicted day.

Green highlights cover the five days before estimated ovulation and the ovulation day; lavender identifies the estimated ovulation day itself. Dark rose marks your entered last period start, and light pink marks following estimated period starts. The calendar begins with the entered cycle, even if some dates have passed.

Ovulation is the release of an egg from an ovary. The egg moves into a fallopian tube, where fertilization may occur if sperm are present. Ovulation timing varies between people and cycles; a calendar estimate cannot establish whether an egg has actually been released.

Cervical mucus may become clearer, wetter, and more slippery around ovulation. Resting body temperature can rise slightly afterward. Some people notice mild discomfort, while others notice no symptoms. Symptoms alone cannot reliably pinpoint ovulation, and this calculator does not measure these signs. Severe or persistent pain needs medical assessment.