Calendar estimates only — not a contraception or fertility medical diagnosis.
Ovulation Calculator
100% Free • Instant Results • No Signup
Estimate ovulation day and fertile window from cycle length and last period.
Estimated ovulation
Fri, Jul 17, 2026
Fertile window is approximate (~5 days before + day after).
Fertile fromSun, Jul 12, 2026
Fertile untilSat, Jul 18, 2026
Steps
- Enter LMP and cycle length
- See ovulation day
- Review fertile window
Related
FAQ
Are results official?
No—quick estimates only.
Is data saved?
No. Calculations run in your browser.