Ovulation Calculator
Estimate your ovulation date and fertile window based on your cycle.
How to Use
Enter the first day of your last period and your average cycle length. Click Calculate to see your estimated ovulation date and fertile window.
How Ovulation Is Estimated
Ovulation typically occurs approximately 14 days before the start of your next period. The fertile window is estimated as 5 days before ovulation through 1 day after ovulation, as sperm can survive in the reproductive tract for up to 5 days.
Frequently Asked Questions
When do I ovulate?
Ovulation typically occurs about 14 days before your next expected period. For a 28-day cycle, this would be around day 14. Use this calculator to get a personalised estimate based on your cycle length.
Can I use this for contraception?
This calculator should not be relied upon as a sole method of contraception. Ovulation timing can vary from cycle to cycle due to stress, illness and hormonal changes. Consult a healthcare provider for reliable contraception options.