Period Calculator
Predict your next period, ovulation day, and fertile window using your average cycle length.
Period Calculator
Predict your next period, ovulation day, and fertile window based on your typical cycle length
Most cycles range between 24 and 35 days.
Ovulation typically occurs 14 days before your next period.
6 cycles
🩸Next period starts
Sunday, March 1, 2026
Ends Thursday, March 5, 2026
✨Ovulation day
Sunday, February 15, 2026
Fertile window Feb 10, 2026 – Feb 16, 2026
⏱️Cycle length
28 days
5 day period
📅Projected cycles
6 upcoming
Mar 1, 2026 → Jul 19, 2026
Upcoming cycle timeline
We project the next 6 cycles using your averages. Actual timing can shift with stress, travel, postpartum changes, or hormonal contraception.
| Cycle | Period | Ovulation | Fertile window | Days until |
|---|---|---|---|---|
| Cycle 1 | Mar 1, 2026 – Mar 5, 2026 | Feb 15, 2026 | Feb 10, 2026 – Feb 16, 2026 | Happening now |
| Cycle 2 | Mar 29, 2026 – Apr 2, 2026 | Mar 15, 2026 | Mar 10, 2026 – Mar 16, 2026 | 28 days |
| Cycle 3 | Apr 26, 2026 – Apr 30, 2026 | Apr 12, 2026 | Apr 7, 2026 – Apr 13, 2026 | 56 days |
| Cycle 4 | May 24, 2026 – May 28, 2026 | May 10, 2026 | May 5, 2026 – May 11, 2026 | 84 days |
| Cycle 5 | Jun 21, 2026 – Jun 25, 2026 | Jun 7, 2026 | Jun 2, 2026 – Jun 8, 2026 | 112 days |
| Cycle 6 | Jul 19, 2026 – Jul 23, 2026 | Jul 5, 2026 | Jun 30, 2026 – Jul 6, 2026 | 140 days |
Cycle insights
- • Track at least three months to refine your average cycle length.
- • Ovulation predictor kits or basal temperature tracking can confirm fertile days.
- • Stress, illness, and travel can delay ovulation or shorten the luteal phase.
Important notes
- • This tool offers estimates and is not a substitute for medical advice.
- • Irregular cycles, PCOS, postpartum recovery, or hormonal birth control may alter results.
- • See a clinician if your period is consistently very short, very long, or absent.