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Free toolPeriod & cycle calculator
Find your next period dates, work out your average cycle length, and see whether it is in the usual range. Everything stays on your phone.
About cycles and PCOS
A cycle is counted from the first day of one period to the first day of the next. For most adults it is between 21 and 35 days. Long, short or very changeable cycles can have many causes, including stress, thyroid problems and PCOS. This calculator cannot diagnose anything; if your cycles are often outside the usual range, talk to a doctor. Read PCOS vs PCOD: what’s the difference?
Questions
What is a normal cycle length?
For adults, a cycle is usually counted from the first day of one period to the first day of the next, and most are between 21 and 35 days. A few days of difference from month to month is normal.
Can this calculator tell me if I have PCOS?
No. Irregular or long cycles are one possible sign of PCOS, but only a doctor can diagnose it, usually with an examination and tests.
Can I use it to avoid or plan a pregnancy?
No. Period predictions are estimates, and they are less reliable when cycles are irregular, as they often are with PCOS. Talk to your doctor about contraception or pregnancy planning.
Is my data saved?
No. The calculation happens on your phone. Nothing you type here is sent or stored.
Talk to your doctor
This article is general information, not medical advice. Your body and your history are your own. Talk to your gynaecologist or doctor before you change a medicine, a diet or how you exercise.
Track every period without thinking about it
Morevie keeps your period dates, symptoms and your doctor’s plan in one place, and makes a summary for your next visit.
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