Ovulation Calculator
Estimate ovulation date and fertile window from cycle timing.
Tool-specific inputs
These inputs aren't part of the dashboard. Adjust them to refine the result above.
How this works
Estimates ovulation about 14 days before the next period and marks the fertile window from five days before through one day after.
Medical disclaimer
Educational tool only — not medical advice. Consult a qualified provider.
Frequently asked questions
What does the Ovulation Calculator estimate?+
It estimates fertile-window timing from last period date and cycle length. The result is a planning estimate, not a diagnosis or personal medical advice.
How accurate is this ovulation result?+
Accuracy depends on the inputs and the limits of the formula. Use the result as a reference point and compare it with real-world outcomes over time.
Can I share my result?+
Yes. Change the inputs, use the copy-link button, and the current values are preserved in the URL for reopening or sharing.
Will my last input be remembered?+
Yes. The calculator saves the latest inputs in this browser so a reload can restore the most recent values.
Should I use this for medical decisions?+
No. These calculators are educational tools. Talk with a qualified clinician before making health, pregnancy, nutrition, or training decisions.