Your cycle changes throughout your life. See what's typical for your age — from your first period to perimenopause.
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Menstrual cycles aren't fixed for life — they tend to shift across different life stages. This tool gives general context for how cycle characteristics commonly change from the teenage years through the reproductive years and into perimenopause.
In the first few years after periods begin, cycles are often longer and irregular. They typically settle into a more predictable pattern in the 20s and 30s, then can shorten and become variable again as perimenopause approaches, usually in the 40s.
This tool gives general information and estimates only — it is not medical advice. If you have concerns, speak to a healthcare professional.
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Explore the calculators →Cycles are often irregular in the teens, more regular through the 20s and 30s, and then become variable again in the 40s as hormone levels fluctuate before menopause.
Yes — many people notice their cycles shorten in their late 30s and 40s. This is a common, normal part of the gradual transition toward menopause.
Perimenopause most commonly begins in the mid-40s, though it can start earlier or later. Changing cycle length and skipped periods are often among the first signs.
In the first couple of years after periods start, the body isn't always ovulating predictably, so cycles can be long, short, or skipped. This usually settles on its own over time.