Calculate your next period date, ovulation, and fertile window.
Average: 28 days (21-35 days is normal)
Average: 5 days (3-7 days is normal)
This calculator provides estimates. Consult a healthcare provider for medical advice.
Enter your information to see results
Understanding your menstrual cycle helps you plan ahead and monitor your reproductive health.
Enter your last period date and cycle length. The fertile window is typically 5 days before ovulation and 1 day after.
Cycle length can vary. This calculator provides estimates based on average cycles and should not be used for birth control.