worldofcalcsOvulation Calculator
Usually 28 days
Most Fertile Window
Tue Sep 15 2026 - Mon Sep 21 2026
Estimated Ovulation
Sun Sep 20 2026
Next Period Starts
Sun Oct 04 2026
About Ovulation Calculator
This calculator estimates your ovulation date and fertile window based on your last menstrual period and cycle length. Ovulation typically occurs 14 days before your next period.
Key Concepts
- Ovulation: When an egg is released from the ovary.
- Fertile Window: The days you are most likely to get pregnant.
- Cycle Length: Days from start of one period to start of the next.
How to Use
- Enter the first day of your last period.
- Enter your average cycle length (21-35 days).
- View your fertile window and ovulation date.