Period Calculator
Track your menstrual cycle and predict future periods, ovulation, and fertile windows.
Calendar Legend
Next Period Expected
Thu, May 21, 2026
Average cycle length (days)
28 days
Regular
Cycle Regularity
Upcoming Periods
Thu, May 21, 2026
Cycle 1
Thu, Jun 18, 2026
Cycle 2
Thu, Jul 16, 2026
Cycle 3
Thu, Aug 13, 2026
Cycle 4
Thu, Sep 10, 2026
Cycle 5
Thu, Oct 8, 2026
Cycle 6
Fertile Windows & Ovulation
May 2 - May 8
Ovulation: May 7
Cycle 1
May 30 - Jun 5
Ovulation: Jun 4
Cycle 2
Jun 27 - Jul 3
Ovulation: Jul 2
Cycle 3
Jul 25 - Jul 31
Ovulation: Jul 30
Cycle 4
Aug 22 - Aug 28
Ovulation: Aug 27
Cycle 5
Sep 19 - Sep 25
Ovulation: Sep 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.