BMI Calculator

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Calculate your Body Mass Index from height and weight, see your category and the healthy weight range for your height. Metric or imperial, free and instant.

cm
ft
in
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Your BMI – kg/m²
Category –
Healthy weight range –
BMI is body weight in kilograms divided by height in metres squared. The healthy range corresponds to a BMI of 18.5 to 24.9. BMI is a general screening tool and does not account for muscle mass or body composition.

About BMI Calculator

The BMI Calculator computes your Body Mass Index from height and weight, in metric (cm, kg) or imperial (ft/in, lb) units. It shows your BMI value, the category it falls into — underweight, normal weight, overweight or obese — and the healthy weight range for your height.

BMI is body weight in kilograms divided by height in meters squared (kg/m²). The standard adult categories are: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, and 30 or above obese. The healthy weight range shown is simply the weights that put your height between BMI 18.5 and 24.9.

It is a quick screening number used by doctors, insurers and fitness plans to flag potential weight-related risk. Because it ignores muscle mass and body composition, treat it as a starting point rather than a verdict. Free and instant, calculated in your browser.

How to use BMI Calculator

  1. Choose metric or imperial units.
  2. Enter your height — centimeters, or feet and inches.
  3. Enter your weight in kilograms or pounds.
  4. Read your BMI, its category and the healthy weight range for your height.

Frequently asked questions

BMI = weight in kilograms ÷ (height in meters)². Imperial inputs are converted automatically, which is equivalent to the formula 703 × weight(lb) ÷ height(in)². The result is expressed in kg/m².

For adults, a BMI of 18.5 to 24.9 is classed as normal weight. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is obese. The calculator shows the weight range matching 18.5–24.9 for your height.

Often not. BMI cannot tell muscle from fat, so muscular people can read as overweight while having low body fat. Pairing BMI with a body fat estimate or waist measurement gives a fuller picture.

The adult categories used here do not. Children and teens are assessed with age- and sex-specific BMI percentiles, so use a pediatric growth chart for anyone under 18.

BMI is a general screening estimate, not medical advice. It ignores body composition, age and other risk factors, so discuss your result with a healthcare professional before changing diet, exercise or medication.
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