Free ยท No signup ยท Works offline
Ovulation Calculator
Free ovulation calculator: your fertile window and likely ovulation day from the first day of your last period and your cycle length, for the next 3 cycles, with the due date if you conceive.
Your most fertile days
Pick the first day of your last period.
๐ก Good to know
- This is a calendar estimate. Ovulation can move by several days from month to month.
- Ovulation tests (LH strips) or tracking temperature give a closer answer.
- If you've been trying for a year (6 months if you're over 35), talk to a doctor.
Not medical advice and not a method of contraception. ๐ Everything stays on your device.
๐ Official sources: WHO: sexual and reproductive health
We build every tool from the official rules and re-check them when they change. Always confirm with the official source before you rely on a result.
๐ ๏ธ Spotted a mistake or an out-of-date rule? Tell us
Related tools
Questions people ask
When does ovulation happen?+
Usually about 14 days before your next period: around day 14 of a 28-day cycle.
What is the fertile window?+
The 5 days before ovulation and the day of ovulation itself.