About Period Calculator
Predict upcoming menstrual cycle start dates and cycle regularity.. Designed for accurate, instantaneous calculations with zero wait time.
Formula
Next Cycle Date = Previous Period Start + Cycle Length
Example Calculation
Cycle beginning on the 5th with a 28-day cadence will next commence on the 3rd of the following month.
How to Use
- Enter your values into the form fields above.
- The calculation updates immediately in real time.
- Inspect the main summary and secondary breakdowns below.