Ovulation Calculator

All tools

Find your most likely ovulation day and fertile window from your last period, cycle length and luteal phase. Free and instant.

days
days
Days from ovulation to your next period (usually 12–16).
Estimated ovulation –
Fertile window –
Next period –
Next cycle ovulation –
Ovulation is estimated as your next period minus the luteal phase. The fertile window spans about five days before ovulation through the day after. An estimate only — not a contraceptive method.
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