Period
Calculator
Predict upcoming menstrual periods, ovulation dates, and fertile windows based on cycle length and last period date.
Cycle Settings
days
days
Next Period
Oct 15, 2026
Current Cycle Day
Day 1
Legend
PeriodMenstruation days
OvulationEstimated ovulation
FertileFertile window
Predictions
| # | Period Start | Period End | Ovulation | Fertile Window |
|---|---|---|---|---|
| 1 | Oct 15, 2026 | Oct 19, 2026 | Oct 29, 2026 | Oct 24, 2026 – Oct 29, 2026 |
| 2 | Nov 12, 2026 | Nov 16, 2026 | Nov 26, 2026 | Nov 21, 2026 – Nov 26, 2026 |
| 3 | Dec 10, 2026 | Dec 14, 2026 | Dec 24, 2026 | Dec 19, 2026 – Dec 24, 2026 |
| 4 | Jan 7, 2027 | Jan 11, 2027 | Jan 21, 2027 | Jan 16, 2027 – Jan 21, 2027 |
| 5 | Feb 4, 2027 | Feb 8, 2027 | Feb 18, 2027 | Feb 13, 2027 – Feb 18, 2027 |
| 6 | Mar 4, 2027 | Mar 8, 2027 | Mar 18, 2027 | Mar 13, 2027 – Mar 18, 2027 |
Predictions
Cycle 1
Period
Oct 15, 2026 – Oct 19, 2026
Ovulation
Oct 29, 2026
Fertile Window
Oct 24, 2026 – Oct 29, 2026
Cycle 2
Period
Nov 12, 2026 – Nov 16, 2026
Ovulation
Nov 26, 2026
Fertile Window
Nov 21, 2026 – Nov 26, 2026
Cycle 3
Period
Dec 10, 2026 – Dec 14, 2026
Ovulation
Dec 24, 2026
Fertile Window
Dec 19, 2026 – Dec 24, 2026
Cycle 4
Period
Jan 7, 2027 – Jan 11, 2027
Ovulation
Jan 21, 2027
Fertile Window
Jan 16, 2027 – Jan 21, 2027
Cycle 5
Period
Feb 4, 2027 – Feb 8, 2027
Ovulation
Feb 18, 2027
Fertile Window
Feb 13, 2027 – Feb 18, 2027
Cycle 6
Period
Mar 4, 2027 – Mar 8, 2027
Ovulation
Mar 18, 2027
Fertile Window
Mar 13, 2027 – Mar 18, 2027