Free · Health · Pregnancy & Cycle
Ovulation Calculator
Estimate ovulation date, fertile window, and next period from the last period and typical cycle length.
- Checked formula
- Private in your browser
- No signup
Result
Your calculation
- Estimated ovulation
- Monday, August 3, 2026
- Estimated fertile window
- Wednesday, July 29, 2026 to Tuesday, August 4, 2026
- Estimated next period
- Monday, August 17, 2026
Cycle-based estimates cannot confirm ovulation and are less reliable with irregular cycles.
How to use this calculator
- Enter current measurements as accurately as practical.
- Calculate to see the estimate, range, and method details.
- Use the result as context, and discuss health decisions with a qualified clinician.
Use the result with context
Health results are educational estimates, not a diagnosis or treatment recommendation. A qualified clinician can interpret measurements in the context of your health.