- Not a method of contraception: the calendar method is only an estimate and does not reliably prevent pregnancy – ovulation can shift at any time. This calculator does not replace medical advice.
- Ovulation (estimated)
- around Monday, 28 September 2026
- Fertile window (estimated)
- 23/09/2026 – 29/09/2026
- Next period
- around Monday, 12 October 2026
- Next 3 cycles
| Cycle | Period starts | Fertile days (approx.) | Ovulation (approx.) | Next period |
|---|
| 1 | 14/09/2026 | 23/09/2026 – 29/09/2026 | 28/09/2026 | 12/10/2026 |
| 2 | 12/10/2026 | 21/10/2026 – 27/10/2026 | 26/10/2026 | 09/11/2026 |
| 3 | 09/11/2026 | 18/11/2026 – 24/11/2026 | 23/11/2026 | 07/12/2026 |