First period calculator

There isn't a magic calculator that can pinpoint the exact day of your first period, because every girl's body has its own rhythm. Your first period can arrive anytime between roughly 9 and 15 years old, sometimes later, with the average being around 12 years old.

Instead of a specific date on the calendar, your body gives you some clear clues throughout puberty:

• Breasts starting to grow, which is usually the first visible sign, and your period typically arrives about 2 years later, but this varies a lot.
• Pubic and underarm hair, which usually appears shortly after breast buds, although having hair earlier is also super normal.
• The growth spurt, that phase where you grow very rapidly in a short time, and your period usually comes about a year after the peak growth spurt phase, and this also varies a lot.
• Clear or whitish discharge in your underwear, which can start a few months before your first period. If it changes color, smells bad, or itches, tell an adult.

When to talk to an adult

No period by age 15, or no breast growth or other signs of puberty by age 13 are reasons to tell an adult and see a doctor to make sure everything is okay. Breasts or hair before age 8 also warrant a doctor's visit, and it's usually nothing serious. Periods before age 9, or any bleeding or pink or brown spotting before age 9, are also reasons to tell an adult so a doctor can check. ah, and if you want to see which signs your body is already showing, there's a quiz here on the site: how close is my first period?. It takes about a minute.