Calculators Tool
Ovulation Calculator
Predict ovulation date and fertile window for the next few cycles.
Privacy-first workflows
Fast and simple
100% Free, no signup
Most cycles are 21–35 days; the average is 28.
Cycle 1
Period start9 Sept 2026
Fertile window18 Sept 2026 → 24 Sept 2026
Likely ovulation23 Sept 2026
Next period expected7 Oct 2026
Cycle 2
Period start7 Oct 2026
Fertile window16 Oct 2026 → 22 Oct 2026
Likely ovulation21 Oct 2026
Next period expected4 Nov 2026
Cycle 3
Period start4 Nov 2026
Fertile window13 Nov 2026 → 19 Nov 2026
Likely ovulation18 Nov 2026
Next period expected2 Dec 2026
Note: Ovulation calculators are statistical estimates. Cycle irregularities, stress, illness, or hormonal changes can shift ovulation. Consult a doctor for fertility planning.
How it works
How to use the ovulation calculator
STEP 01
Enter the first day of your last period.
STEP 02
Set your average cycle length.
STEP 03
See ovulation date, fertile window, and next period for each upcoming cycle.
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