Period Calculator
Track your menstrual cycle, predict your next period, and calculate your fertile window. Stay informed about your reproductive health with accurate cycle predictions.
Period Tracking
Enter your cycle details to predict your next period and fertile days
Default is 28 days. Range: 22-44 days
Default is 5 days. Range: 3-10 days
Next Period
Enter your cycle details to predict your next period.
Understanding Your Cycle
Menstrual Cycle Phases
- Menstrual Phase: Days 1-5 (period bleeding)
- Follicular Phase: Days 1-13 (egg development)
- Ovulation: Around day 14 (egg release)
- Luteal Phase: Days 15-28 (preparation for pregnancy)
Calculation Method
- Next Period: LMP + Cycle Length
- Ovulation: LMP + (Cycle Length - 14)
- Fertile Window: Ovulation ± 2 days
- Forecast: Repeat for next 6 cycles
Fertility & Timing
- Most fertile: 2 days before ovulation
- Fertile window: 5 days total around ovulation
- Sperm survival: Up to 5 days in reproductive tract
- Egg survival: 12-24 hours after ovulation
Important Notes
- This calculator provides estimates based on average cycles
- Actual cycles can vary due to stress, illness, or lifestyle
- Track your cycle for 3+ months for better accuracy
- Consult healthcare providers for irregular cycles