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BMI Calculator

Body mass index and healthy rangeRuns locally · nothing uploaded

BMI
22.2
Category
Normal
Healthy weight range
125.3 lb – 168.6 lb

WHO adult categories: <18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, ≥30 obese. For reference only, not medical advice.

Estimates based on general formulas, for information only. Not a substitute for professional medical advice, diagnosis or treatment.

Also works as:body mass index

How it works

When to use it

  • Quickly check whether an adult's weight is in a healthy range.
  • Turn a target BMI into a target weight range.

Formula

BMI = weight (kg) ÷ height (m)²

Imperial: BMI = 703 × weight (lb) ÷ height (in)².

WHO: < 18.5 underweight; 18.5–24.9 normal; 25–29.9 overweight; ≥ 30 obese

Worked example

Given: 5 ft 9 in (69 in), 150 lb

  1. Height = 69 × 0.0254 = 1.7526 m; weight = 150 × 0.4536 = 68.04 kg.
  2. BMI = 68.04 ÷ 1.7526² ≈ 22.15.
  3. Healthy range at this height: 18.5–24.9 → about 125–169 lb.

Result: BMI 22.15, in the normal range.

Reading the result

  • BMI doesn't distinguish muscle from fat, so muscular people can score high without excess fat.
  • Waist size adds information about abdominal fat, which carries more health risk.

Limitations

  • Not for children and teens (use BMI-for-age percentiles), or during pregnancy.
  • Some groups have different risk at the same BMI (for example, many Asian populations at lower cut-offs). Not a diagnosis.

Sources

  • WHO: Body mass index (BMI) classification
  • CDC: About Adult BMI

How to use

  1. 1Choose metric (cm/kg) or imperial (ft-in/lb).
  2. 2Enter height and weight.
  3. 3See your BMI and category.

FAQ

How is BMI calculated?

BMI = weight (kg) ÷ height (m)². For 70 kg and 1.75 m, BMI is 22.9.

What is a healthy BMI?

By WHO adult categories, 18.5–24.9 is normal, 25–29.9 overweight and 30+ obese. BMI is a screening measure, not a diagnosis.

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