Free Tool · Yogacruz
Ovulation Calculator
Find your next ovulation date and fertile window, plus a full month-by-month ovulation calendar for the next 12 months — based on your last period, cycle length, and luteal phase.
Ovulation day is estimated as cycle length minus luteal phase length from the start of your last period; the fertile window covers 5 days before ovulation through the day after. Predictions further into the future assume your cycle length stays constant — real cycles vary, especially with stress, illness, or irregular cycles, so treat months further out as an approximate guide.
Frequently Asked Questions
How accurate is a month-wise ovulation prediction?
Near-term predictions (this cycle and next) tend to be reasonably reliable for people with regular cycles. Predictions many months ahead assume your cycle length never changes, which is rarely exactly true — use distant months as a general guide rather than an exact date.
Why does one month sometimes show no ovulation date?
If your cycle length is longer than the number of days in a given month, an ovulation date can occasionally skip over that calendar month entirely and land in the next one instead.
What if my cycles are irregular?
This calculator assumes a consistent cycle length. If your cycles vary significantly month to month, predictions — especially for distant months — will be less reliable. Tracking basal body temperature, cervical mucus, or using ovulation predictor kits gives a more accurate real-time picture.
