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
Dec 2, 2026
Current Cycle Day
Day 1
Legend
PeriodMenstruation days
OvulationEstimated ovulation
FertileFertile window
Predictions
| # | Period Start | Period End | Ovulation | Fertile Window |
|---|---|---|---|---|
| 1 | Dec 2, 2026 | Dec 6, 2026 | Dec 16, 2026 | Dec 11, 2026 – Dec 16, 2026 |
| 2 | Dec 30, 2026 | Jan 3, 2027 | Jan 13, 2027 | Jan 8, 2027 – Jan 13, 2027 |
| 3 | Jan 27, 2027 | Jan 31, 2027 | Feb 10, 2027 | Feb 5, 2027 – Feb 10, 2027 |
| 4 | Feb 24, 2027 | Feb 28, 2027 | Mar 10, 2027 | Mar 5, 2027 – Mar 10, 2027 |
| 5 | Mar 24, 2027 | Mar 28, 2027 | Apr 7, 2027 | Apr 2, 2027 – Apr 7, 2027 |
| 6 | Apr 21, 2027 | Apr 25, 2027 | May 5, 2027 | Apr 30, 2027 – May 5, 2027 |
Predictions
Cycle 1
Period
Dec 2, 2026 – Dec 6, 2026
Ovulation
Dec 16, 2026
Fertile Window
Dec 11, 2026 – Dec 16, 2026
Cycle 2
Period
Dec 30, 2026 – Jan 3, 2027
Ovulation
Jan 13, 2027
Fertile Window
Jan 8, 2027 – Jan 13, 2027
Cycle 3
Period
Jan 27, 2027 – Jan 31, 2027
Ovulation
Feb 10, 2027
Fertile Window
Feb 5, 2027 – Feb 10, 2027
Cycle 4
Period
Feb 24, 2027 – Feb 28, 2027
Ovulation
Mar 10, 2027
Fertile Window
Mar 5, 2027 – Mar 10, 2027
Cycle 5
Period
Mar 24, 2027 – Mar 28, 2027
Ovulation
Apr 7, 2027
Fertile Window
Apr 2, 2027 – Apr 7, 2027
Cycle 6
Period
Apr 21, 2027 – Apr 25, 2027
Ovulation
May 5, 2027
Fertile Window
Apr 30, 2027 – May 5, 2027