Period Calculator
Estimate your next period and fertile window with this easy-to-use calculator.
Estimate your next period and fertile window with this easy-to-use calculator.
Use the calendar to select the first day of your most recent menstrual period.
Input the average number of days in your menstrual cycle (from the first day of one period to the first day of the next).
Provide the average number of days your period typically lasts.
The calculator will display your estimated next period dates and your fertile window.
The Period Calculator helps you predict your future menstrual cycles and identify your most fertile days. By providing the start date of your last period and your average cycle length, you can get an estimate of when to expect your next period and when ovulation is likely to occur. This tool is helpful for cycle tracking, family planning, or simply staying informed about your body's rhythm.