The average menstrual cycle is 28 days long.Cycles can range anywhere from 21 to 35 days in adults and from 21 to 45 days in young teens.
An estimated menstrual cycle period can be calculated by following steps 1 through 3:
- You need to determine the first day of your last menstrual period.
- Knowing your menstrual cycle length. This is the number of days from the first day of your period until the last day before your next period.
- Enter the date and menstrual cycle length, click the button and you'll get the calculation.