What Is a Period Calculator?
A period calculator predicts when your next periods will start based on your menstrual cycle history. This helps you prepare for upcoming periods and notice irregularities early.
How Does It Work?
Your menstrual cycle length is the number of days from the first day of one period to the first day of the next. The calculator adds your cycle length repeatedly to your last period date to project future period start dates.
What Is a Normal Cycle?
A typical menstrual cycle ranges from 21 to 35 days, with 28 days being the average. Variations of a few days between cycles are completely normal. Consistently irregular cycles (varying by more than 7-9 days) may warrant a conversation with your healthcare provider.
Tips for Tracking
- Track at least 3 cycles to establish your average cycle length.
- Note the first day of bleeding (spotting doesn't count) as Day 1.
- Stress, travel, weight changes, and illness can temporarily affect your cycle.