Ovulation Calculator: Your Ovulation Date and Fertile Days
Enter the first day of your last period and your cycle length to estimate when you are likely to ovulate and your most fertile days.
- Nothing you type is stored
- Free
- No signup
Estimated ovulation
Wed, 18 Nov 2026
- Fertile days start
- Fri, 13 Nov 2026
- Fertile days end
- Thu, 19 Nov 2026
- Next period expected
- Wed, 2 Dec 2026
- Ovulation on cycle day
- 14
An estimate for general information, not medical advice. Calendar dates are not a reliable method of birth control.
Next 6 cycles
| Period starts | Ovulation | Fertile from | Fertile to |
|---|---|---|---|
| Wed, 4 Nov 2026 | Wed, 18 Nov 2026 | Fri, 13 Nov 2026 | Thu, 19 Nov 2026 |
| Wed, 2 Dec 2026 | Wed, 16 Dec 2026 | Fri, 11 Dec 2026 | Thu, 17 Dec 2026 |
| Wed, 30 Dec 2026 | Wed, 13 Jan 2027 | Fri, 8 Jan 2027 | Thu, 14 Jan 2027 |
| Wed, 27 Jan 2027 | Wed, 10 Feb 2027 | Fri, 5 Feb 2027 | Thu, 11 Feb 2027 |
| Wed, 24 Feb 2027 | Wed, 10 Mar 2027 | Fri, 5 Mar 2027 | Thu, 11 Mar 2027 |
| Wed, 24 Mar 2027 | Wed, 7 Apr 2027 | Fri, 2 Apr 2027 | Thu, 8 Apr 2027 |
How to use
- Enter the first day of your last period.
- Enter your usual cycle length (and luteal phase if you know it).
- See your estimated ovulation date, fertile days and the next 6 cycles.
Good to know
Ovulation usually happens about 14 days before the next period starts (the luteal phase is fairly steady at 12–16 days). So with a 28-day cycle it is around day 14; with a 32-day cycle around day 18.
The fertile window is the 5 days before ovulation, ovulation day and the day after, because sperm can survive about 5 days and the egg about a day (Wilcox et al., NEJM 1995). Sex every 1–2 days in that window gives the best chance when trying for a baby.
Calendar dates are only estimates: ovulation shifts with stress, illness, travel and conditions like PCOS, which is common in India. Ovulation test kits, basal temperature or cervical mucus give a closer picture. This calculator is not a method of contraception. If you have been trying for 12 months (6 months if over 35), see a doctor.
Questions
When do I ovulate in a 28-day cycle?
Usually around day 14, counting the first day of your period as day 1. Your fertile window would be about days 9–15.
Can I ovulate with irregular periods?
Yes, but the timing is harder to predict. With PCOS or very irregular cycles, talk to a gynaecologist and consider ovulation tests.
Can I use this to avoid pregnancy?
No. Calendar predictions can be off by several days and are not reliable contraception. Ask a doctor about safe birth-control options.
What is the luteal phase?
The days from ovulation to your next period, usually 12–16. If you know yours from tracking, enter it under More options.
Is my data saved?
No. Your dates stay on your device; nothing is stored or sent.