Ovulation & Fertility Calculator
Free ovulation calculator. Discover your exact fertile window, ovulation date, and next period start date to maximize your chances of getting pregnant.
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Tip: The luteal phase is the time between ovulation and your next period. It is almost always exactly 14 days for most women, even if your total cycle length varies. Leave as 14 if unsure.
Enter the first day of your last period to calculate your fertile window.
How to Use the Ovulation & Fertility Calculator
Using our ovulation calculator is simple and fast. Just follow these steps:
- Determine which calculation mode you need.
- Enter your values into the input fields.
- The result will automatically calculate and display below.
Understanding Your Results
The results provided by this tool are calculated instantly using standard mathematical formulas. If you see an unexpected result, ensure your input values are correctly formatted without any extra characters.