A free online BMI calculator for men, women, and kids. Enter your height and weight (kg or lbs) and watch the gauge move in real time — one calculator handles adults and kids/teens automatically, no separate tool to hunt for.
Body Mass Index remains the fastest, most widely used way to screen whether your weight falls in a healthy range for your height. This BMI calculator is built to work for the whole family: one BMI calculator online that handles adult men and women, and automatically becomes a child BMI calculator the moment you enter an age under 20 — no separate tool to hunt for.
The BMI formula — weight in kilograms divided by height in meters squared — is identical whether you're using this as a BMI calculator for women or a BMI calculator for men. The World Health Organization's adult BMI chart (underweight, healthy weight, overweight, and the three classes of obesity) applies the same way to both sexes, so a male BMI calculator and a female BMI calculator are really the same tool under the hood. Some people simply type bmi calculator men or bmi calculator women into search; others look for bmi calculator male, bmi calculator female, bmi calculator for female, a women bmi calculator, or a womens bmi calculator specifically — they all land on the same accurate numbers here. If what you actually want is a bmi calculator women age adjusts for automatically, this is it: enter 20 or older and you get the standard adult BMI chart; enter anything younger and it switches to age-and-sex-specific percentiles instead, which is the medically appropriate approach for a growing body rather than a flat adult cutoff.
For anyone under 20, this becomes a genuine child BMI calculator rather than a shrunk-down adult one. Kids' and teens' bodies change shape constantly as they grow, so a flat "25 is overweight" rule doesn't hold up the way it does for adults. Instead, this bmi calculator kids and parents can rely on uses the CDC's official BMI-for-age growth charts: your child's BMI is compared against thousands of other children of the same age, in months, and sex, producing a percentile rather than a raw cutoff. A percentile under the 5th is flagged as underweight, 5th up to the 85th is a healthy weight, 85th up to the 95th is overweight, and 95th and above is classified as obesity — the same thresholds pediatricians use. Because this bmi calculator by age adjusts automatically, there's no separate kids' page to find; you just enter height, weight, and age like normal, for a boy or a girl.
Whether you prefer kilograms or pounds, unit switching is instant and never loses whatever you've already typed in — so a bmi calculator kg with age behaves exactly like one worked out in pounds and years. Alongside your BMI number, you get the full adult BMI chart for context, your healthy weight range in whichever units you're using, BMI Prime (your BMI expressed as a simple ratio to the upper healthy limit of 25), and Ponderal Index, a height-cubed alternative that's less skewed for people who are unusually tall or short.
Every calculation happens instantly in your browser as you type, with a live gauge showing exactly where your result lands — underweight, healthy, overweight, or obese — instead of making you cross-reference a static chart by hand. You can save results over time to see your trend with no account required, and export a clean image of your result to share. It's the same free BMI calculator whether you're checking your own numbers, a partner's, or a child's: enter height, weight, and age, and it figures out the rest.
