Ovulation Calculator

Estimate your ovulation date and fertile window based on your cycle length.

First day of last period:

Average cycle length (days): Most cycles range from 21-35 days.

适用场景：想知道下次排卵日期、计划怀孕或避孕的女性。

使用方法：输入末次月经第一天和平均周期长度，点击计算即可看到排卵日和 fertile window。

结果解读：排卵日前5天到排卵日当天是 fertile window，其中排卵日前2天受孕概率最高。

We estimate ovulation by subtracting 14 days from your cycle length. The luteal phase (post-ovulation) is relatively consistent at 12-16 days.

This is an estimate only. For precise tracking, combine with BBT, cervical mucus, or LH strips.