Menstrual & Ovulation Calculator
Calendar-based estimates — your data never leaves this device.
Cycle details
28 days
21 days 40 days
Predictions
- Next period (est.)
- —
- Ovulation window (est.)
- —
- Peak ovulation: —
Cycle timeline
- Period
- Lower risk
- Fertile
- Ovulation
Enter your last period date to see the timeline.