12 · Calculators

BMI Calculator

Enter your height and weight to get your body mass index, the standard adult category, and the weight range that counts as healthy for your height.

Units

For adults 18+. BMI is a screening number, not a diagnosis.

Your BMI

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How to use the bmi calculator

  1. Choose metric or US units.
  2. Enter your weight and height.
  3. Read your BMI, its category and the healthy weight range for your height.

What BMI means — and what it doesn’t

BMI is weight in kilograms divided by height in metres squared. For adults, the World Health Organization uses these ranges: under 18.5 is underweight, 18.5–24.9 is a healthy weight, 25–29.9 is overweight, and 30 or more is obesity.

BMI is a quick screening number for populations, not a diagnosis for individuals. It doesn’t distinguish muscle from fat, and it’s less accurate for athletes, older adults, pregnant people and some ethnic groups. It isn’t used the same way for children and teens. If you have concerns about your weight, talk to a health professional.

Examples

70 kg, 175 cm

BMI 22.9 · healthy weight · range 56.7–76.3 kg

160 lb, 5 ft 10 in

BMI 23.0 · healthy weight · range 128.9–173.5 lb

Questions

Is BMI accurate?

It’s a rough guide. It can overestimate body fat in muscular people and underestimate it in people who have lost muscle. Waist measurement and other checks give a fuller picture.

Can children use this?

No. Children and teens are assessed with age- and sex-specific BMI percentiles, which this calculator doesn’t use.

Are my measurements stored?

No. The calculation happens in your browser and nothing is saved or sent.