📅 Ovulation Calculator
Calculate your fertile window and ovulation date
How Ovulation Calculation Works
Formula
Ovulation Day = Next Period Date − 14 days
- 1Enter the first day of your last period and your average cycle length.
- 2The calculator estimates your next period date.
- 3Ovulation typically occurs 14 days before the next period.
- 4The fertile window spans 5 days before ovulation through 1 day after.
- 5A calendar view highlights your most fertile days.
About Ovulation Calculator
Calculate your most fertile days and ovulation date based on your menstrual cycle. Track your fertility window to plan or prevent pregnancy. Free ovulation calendar.
Frequently Asked Questions
How accurate is an ovulation calculator?
It provides an estimate based on average cycle patterns. Actual ovulation can vary by several days. For more accuracy, combine with basal body temperature tracking or ovulation test kits.
When is the best time to conceive?
The highest chance of conception is 1-2 days before ovulation. Sperm can survive up to 5 days, so the entire fertile window (5 days before to 1 day after ovulation) offers good chances.
What if my cycle is irregular?
Irregular cycles make prediction less reliable. Track several cycles to find your shortest and longest, then calculate a range. Consider using ovulation predictor kits for better accuracy.