All content within this page has been reviewed and endorsed by
Dr Tariq Miskry, Consultant Gynaecologist & Obstetrician
Maybe you’re planning a day at the beach. Maybe you have a sleepover with friends coming up. Or maybe you just want to know when to stash some extra Always Ultra in your bag, so you’re not caught off guard by your monthly flow.
Knowing how to calculate your menstrual cycle is easy and can give you a peace of mind.
So, here’s how to do it.
How to calculate your menstrual cycle
In order to calculate your menstrual cycle, you’ll need to learn how to track your cycle.
Don’t worry. It’s pretty simple. All you need to do is mark down when your period started on a calendar for a few months in order to figure out how to count your period cycle days and to calculate the average length of your menstrual cycle.
How to count the days in your menstrual cycle
Here’s how it works. Mark the first day of your period on the calendar. The first day of your period is Day 1 of your menstrual cycle. Starting on the first day of your period, start counting.
The day before your next period is the last day of your menstrual cycle. That’s when you stop counting. That’s how many days you had in your menstrual cycle that month. For instance, if you got your period on June 5 and your next period came on July 2, your cycle length was 27 days that month.
Calculating your average menstrual cycle length
If you do this for a few months, you’ll know how to count your period cycle days and you’ll be able to figure out your average cycle length.
Do this by adding up the number of days in each cycle. Then divide this number by the number of cycles (aka the number of times you’ve had your period) since counting. This will give you the average number of days between each period, or your average cycle length.
How to know when your next period is due
Now, figuring out when your next period will come is easy as pie. Starting on the first day of your last period, just count out the average number of days between your periods (aka your average cycle length that you calculated) and that gives you the projected start date of your next period.
Voila! Now you know how to calculate your cycle. Calculating your period isn’t an exact science but knowing how to calculate your menstrual cycle will give you a good approximation of when your period will come.
Your period may not come regularly. In fact, when you first start menstruating, it’s totally normal for your period to be irregular. It may take up to a year or two for your body to get into a regular pattern so keep on tracking.
Did all this make you a little cross-eyed? Don’t worry. You can read up more about this on always.com, so check online and use the period calendar on our website. Knowing how to calculate your__ menstrual cycle__ is a big help for being prepared and confident around your period.
Now that you know how to calculate your cycle, you may want to stock up on Always Ultra pads before you think your period will start. They have an absorbent core that turns liquid into gel – and gel can’t leak – so you’ll feel confident and protected on your period. Stash some in your bag or locker so you’ll always be prepared.