Period Calculator
Track your menstrual cycle and predict future periods, ovulation, and fertile windows.
Calendar Legend
Next Period Expected
Thu, Aug 20, 2026
Average cycle length (days)
28 days
Regular
Cycle Regularity
Upcoming Periods
Thu, Aug 20, 2026
Cycle 1
Thu, Sep 17, 2026
Cycle 2
Thu, Oct 15, 2026
Cycle 3
Thu, Nov 12, 2026
Cycle 4
Thu, Dec 10, 2026
Cycle 5
Thu, Jan 7, 2027
Cycle 6
Fertile Windows & Ovulation
Aug 1 - Aug 7
Ovulation: Aug 6
Cycle 1
Aug 29 - Sep 4
Ovulation: Sep 3
Cycle 2
Sep 26 - Oct 2
Ovulation: Oct 1
Cycle 3
Oct 24 - Oct 30
Ovulation: Oct 29
Cycle 4
Nov 21 - Nov 27
Ovulation: Nov 26
Cycle 5
Dec 19 - Dec 25
Ovulation: Dec 24
Cycle 6
Understanding Your Cycle
A typical menstrual cycle lasts 21-35 days. The cycle has four phases: menstruation (days 1-5), follicular phase (days 1-13), ovulation (day 14), and luteal phase (days 15-28). Tracking helps identify patterns.
Benefits of Tracking
Period tracking helps you prepare for your period, identify irregular cycles, optimize conception timing if trying to conceive, and notice health changes to discuss with your doctor.
When to See a Doctor
Consult a healthcare provider if your cycle is consistently shorter than 21 days or longer than 35 days, you miss periods, have very heavy bleeding, or experience severe pain.