Period Calculator
Predict your next period dates based on your average cycle length. Track upcoming periods for the next several months.
Select your last period date.
How It Works
This calculator predicts future period start dates by adding your cycle length repeatedly from your last period date. A normal cycle length ranges from 21 to 35 days.
Important Notes
- Cycle length can vary month to month.
- Stress, illness, travel, and lifestyle changes can affect timing.
- If your cycle is consistently irregular, consult a healthcare provider.
Disclaimer: This is an estimate based on averages. It does not account for irregular cycles. Consult a healthcare professional for concerns about menstrual health.
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Last updated: 2026-08-08