Period Tracker
Track your menstrual cycle, estimate future periods, and calculate fertile windows for the next 3 months. Simple, private, and 100% free period tracker.
Input Metrics
Note: Track using our tool alongside a dedicated period tracking app for best accuracy.
Following 3 Cycle Predictions
3-Month Predicted calendar
How to Use the Menstrual Period Tracker
Stay ahead of your schedule with our simple cycle prediction calendar. Just follow these steps:
- Select the Start Date of your Last Period from the calendar picker.
- Set the Period Duration slider to specify how many days your bleeding typically lasts (between 2 and 8 days).
- Adjust the Cycle Length slider to input your typical duration from the start of one period to the start of the next (between 21 and 35 days).
- Click Track Cycle to generate predictions for the next 4 periods, a days-until countdown, and a color-coded 3-month fertility/period calendar.
Menstrual Cycle & Fertility Windows Explained
The average menstrual cycle runs on a 28-day timeline, but anything from 21 to 35 days is healthy. The cycle has two main stages: the follicular phase (which includes your period) and the luteal phase (post-ovulation).
By mapping your cycle length, the tool projects your period starts and overlay-calculates fertile windows. Ovulation is assumed to happen 14 days prior to your next period start, creating a fertile window of 6 days surrounding that date.
Frequently Asked Questions
How is the next period calculated? ↓
The next period is calculated by adding your average cycle length (in days) to the start date of your last menstrual period.
What is cycle length vs period duration? ↓
Cycle length is the total number of days between the start of one period and the start of the next. Period duration is the number of days bleeding actually occurs during a single cycle.
Can this tracker tell me when I am fertile? ↓
Yes. The tracker estimates fertile windows based on a standard luteal phase, identifying high fertility days as the 5 days before ovulation up to 1 day after ovulation.
How long is a normal menstrual cycle? ↓
A typical menstrual cycle lasts 28 days, but healthy cycles can range anywhere from 21 to 35 days for adult women.
How should I use this tracker? ↓
Track using our tool alongside a dedicated period tracking app for best accuracy. Record your period start dates each month to calculate your personal average cycle length.