Period planning
Enter the first day of your last period and your recent averages to sketch the next six cycles. Use the dates for gentle planning—not as a promise.
Your dates stay on this device. Nothing you enter here is saved or sent to Flowy.
The calculation
A menstrual cycle starts on the first day of one period and ends the day before the next period begins. This tool adds your average cycle length to your latest start date, then repeats that interval for the next six cycles.
Your period length changes only the displayed bleed range; it does not change the next cycle start calculation.
Good to know
Even cycles that feel regular can move by a few days. Predictions become less reliable further into the future, so treat the six dates as a planning outline rather than a schedule your body must follow.
If your period pattern changes, bleeding is unusually heavy, pain disrupts daily life, or pregnancy is possible, a calculator cannot explain why. Seek appropriate medical advice.
Common questions
The calculator adds your average cycle length to the first day of your last period. It repeats that interval for future estimates and uses your usual period length to show an estimated bleed range.
Cycle timing can change with stress, illness, travel, sleep, life stage, medications, contraception, pregnancy, and many health conditions. An average cannot predict every cycle exactly.
For cycle tracking, day one is generally the first day of menstrual bleeding. Light spotting before full bleeding may be tracked separately.
No. It only compares dates with an average pattern. A late or missed period has many possible causes; take a pregnancy test when relevant and contact a healthcare professional about concerns.
