What is an average cycle length?

While 28 days is often cited, adult menstrual cycles can range from 21 to 35 days. Cycle lengths can also vary from month to month.

Is the first day of my period included?

The cycle length calculation starts on the first day of menstruation. So when calculating between two periods, you would enter the first day of each.

Can this calculator predict my next period?

No, this calculator computes the length of a past cycle. To predict future periods, you would need to average your cycle length over several months and then add that to your last period's start date.

When should I see a doctor about irregular periods?

If your cycles suddenly change, become consistently irregular, or are outside the typical range (21-35 days), it's a good idea to consult a healthcare provider.

Menstrual Cycle Tracker | countbetweendays.com

How the Cycle Tracker Works

Understanding your menstrual cycle length is key to tracking your reproductive health. This tool calculates the number of days from the first day of one period to the first day of the next, giving you your cycle length.

How to Calculate Cycle Length: The Formula

The algorithm calculates the difference between the start dates of two consecutive periods.

Cycle Length = Period 2 Start Date - Period 1 Start Date

Practical Uses for the Cycle Tracker

Health Tracking: Monitor the regularity of your menstrual cycle.
Ovulation Prediction: Understanding your cycle length is the first step in predicting your fertile window.
Pregnancy Planning: Track cycles to help with conception attempts.
Doctor's Appointments: Have accurate cycle data to share with your healthcare provider.

Days Between Periods Calculator

How the Cycle Tracker Works

How to Calculate Cycle Length: The Formula

Practical Uses for the Cycle Tracker

Frequently Asked Questions about the Cycle Tracker

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