Period Calculator
Track your menstrual cycle and predict future periods, ovulation, and fertile windows.
Calendar Legend
Next Period Expected
Wed, Nov 18, 2026
Average cycle length (days)
28 days
Regular
Cycle Regularity
Upcoming Periods
Wed, Nov 18, 2026
Cycle 1
Wed, Dec 16, 2026
Cycle 2
Wed, Jan 13, 2027
Cycle 3
Wed, Feb 10, 2027
Cycle 4
Wed, Mar 10, 2027
Cycle 5
Wed, Apr 7, 2027
Cycle 6
Fertile Windows & Ovulation
Oct 30 - Nov 5
Ovulation: Nov 4
Cycle 1
Nov 27 - Dec 3
Ovulation: Dec 2
Cycle 2
Dec 25 - Dec 31
Ovulation: Dec 30
Cycle 3
Jan 22 - Jan 28
Ovulation: Jan 27
Cycle 4
Feb 19 - Feb 25
Ovulation: Feb 24
Cycle 5
Mar 19 - Mar 25
Ovulation: Mar 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.