Period Calculator
Predict your next period and fertile window.
How Period Prediction Works?
A period calculator estimates your next menstrual cycle and fertile window based on your average cycle length and the first day of your last period. Monitoring these dates helps you track your health, plan for the future, and understand your body's unique rhythm.
What is a Normal Cycle?
A typical menstrual cycle lasts between 28 and 32 days, although cycles as short as 21 days or as long as 35 days can be normal. Period length usually varies from three to seven days.
The Fertile Window
The fertile window is the time in a woman's cycle when pregnancy is possible. It includes the day of ovulation and the several days leading up to it, as sperm can live inside the female body for up to five days.