How is the menstrual cycle calculated?

The menstrual cycle is counted from the first day of one period to the first day of the next. A normal cycle lasts 21 to 35 days, with an average of 28 days.

What are the fertile days?

The most fertile days are the 5 days before ovulation and the day of ovulation itself. Ovulation typically occurs 14 days before the start of the next period.

Is this calculator accurate?

This calculator provides estimates based on regular cycles. If your cycle is irregular, results may vary. It should not be used as a contraceptive method.

What factors affect the menstrual cycle?

Stress, weight changes, intense exercise, travel, medications, and medical conditions can affect the duration and regularity of the menstrual cycle.

Menstrual Cycle Calculator

Predict your next period, fertile days, and ovulation date. Personalized menstrual calendar.

Last period date

Cycle length (days)

Period duration (days)

Months to predict