BMI calculator
Your BMI is your weight in kilograms divided by your height in metres squared. Enter both below for the number and the usual adult range it falls in.
Updated 21 October 2026. Sources named on the page.
- Metric or imperial: kilograms and centimetres, or pounds, feet and inches
- For adults aged 19 and over; the same formula and ranges for women and men
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- Shows the formula, worked examples and what BMI cannot tell you
Calculate your BMI
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The formula, the ranges and worked examples
BMI = weight in kilograms divided by height in metres squared. In pounds and inches the same number is 703 times weight in pounds, divided by height in inches squared.
Commonly used adult BMI ranges
| BMI | Range |
|---|---|
| Below 18.5 | Below the usual adult range |
| 18.5 to 24.9 | Within the usual adult range |
| 25 to 29.9 | Above the usual adult range |
| 30 and over | Well above the usual adult range |
Worked examples
| Weight | Height | Working | BMI |
|---|---|---|---|
| 70 kg | 1.75 m | 70 / (1.75 x 1.75) | 22.9 |
| 95 kg | 1.80 m | 95 / (1.80 x 1.80) | 29.3 |
| 50 kg | 1.60 m | 50 / (1.60 x 1.60) | 19.5 |
| 154 lb | 69 in (5 ft 9 in) | 703 x 154 / (69 x 69) | 22.7 |
Sources: The adult cut points of 18.5, 25 and 30 are the widely used World Health Organization adult ranges; CDC and NHS publish the same formula and ranges for adults
Figures and sources checked 21 October 2026. General information, not medical advice.
Questions
What is BMI?
BMI, or body mass index, is your weight in kilograms divided by your height in metres squared. It is a quick screening number that compares weight with height.
What BMI range is usual for adults?
The commonly used adult ranges are below 18.5, 18.5 to 24.9, 25 to 29.9 and 30 or more. These ranges describe where a number sits; they do not say how healthy any one person is.
How do I calculate BMI in pounds and inches?
Multiply your weight in pounds by 703, then divide by your height in inches squared. For example 154 lb at 69 inches is 703 x 154 / (69 x 69), which is 22.7.
Is BMI different for women and men?
No. The adult formula and the ranges are the same for women and men, so this calculator asks for sex only as an option and does not change the result.
What does BMI not tell you?
BMI does not measure body fat, muscle, bone, where fat is carried, age or ethnicity, so it can mislead for very muscular people and others. It is for adults aged 19 and over, not for pregnancy or medical decisions. Talk to a doctor or an accredited practising dietitian about your own health.
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