What is a normal cycle length?

A normal menstrual cycle ranges from 21 to 35 days. The average is 28 days, but cycles as short as 21 or as long as 35 days are considered normal.

What if my cycle is irregular?

Irregular cycles make prediction harder. Track your period over several months to find your average. If irregularity is significant, consult a healthcare provider.

Can this be used as birth control?

No. This calculator is for informational purposes only and should not be used for contraception. Consult a doctor for family planning advice.

Period Calculator — Next Period Date

The Period Calculator predicts how many days until your next menstrual period based on the start date of your last period and the average length of your cycle. Most cycles range from 21 to 35 days, with 28 days being the average. Use this tool to plan ahead, track your cycle, and stay prepared.

Last Period — Year

Last Period — Month

Last Period — Day

Average Cycle Length(days)

How to Use This Calculator

1
Enter the year, month, and day your last period started.
2
Enter your average cycle length (default is 28 days).
3
Click Calculate to see how many days until your next period.

Frequently Asked Questions

This calculator is based on average cycle length and provides an estimate. Actual periods can vary by a few days due to stress, illness, weight changes, or hormonal fluctuations.

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