BMI Calculator
Find your body mass index in metric or imperial units, see which band it falls in, and the healthy weight range for your height, using WHO's standard or Asian cut-offs.
WHO suggests lower cut-offs for people of South and East Asian descent, who face health risks at a lower BMI.
Your BMI
24.2 healthy weight
- Healthy weight from
- 53.5 kg
- Healthy weight below
- 72.3 kg
A BMI of 24.2 is in the "healthy weight" band. For your height, a healthy weight is 53.5 kg up to just under 72.3 kg.
How it's worked out
- Height in metres
170 cm ÷ 1001.7 m - BMI
70 kg ÷ (1.7 m)²24.2 - Your band
healthy is 18.5 to under 25; overweight from 25; obese from 30Healthy weight
- BMI is a screening measure, not a diagnosis. It doesn't tell muscle from fat and isn't designed for children, pregnancy or athletes.
How BMI works
Body mass index compares your weight with your height. It is the same formula for everyone; only the bands used to read it differ.
BMI = weight (kg) ÷ height (m)²
The bands
- WHO standard: under 18.5 underweight, 18.5 to under 25 healthy, 25 to under 30 overweight, 30 and over obese.
- WHO for Asian populations: under 18.5 underweight, 18.5 to under 23 healthy, 23 to under 27.5 overweight, 27.5 and over obese.
Worked example
At 170 cm and 70 kg, BMI is 70 ÷ 1.70² = 24.2: healthy on the standard bands, but overweight on the Asian cut-offs. For that height, the healthy range is 53.5 kg to just under 72.3 kg (standard) or 66.5 kg (Asian).
Questions people ask
How is BMI calculated?
Weight in kilograms divided by height in metres squared. 70 kg at 1.70 m is 70 ÷ 1.70² = 24.2.
What is a healthy BMI?
On WHO's standard bands, 18.5 to under 25. On the cut-offs WHO suggests for Asian populations, 18.5 to under 23.
Why are there Asian BMI cut-offs?
Research found that people of South and East Asian descent face higher risks of diabetes and heart disease at a lower BMI, so WHO suggests overweight from 23 and obese from 27.5 for these groups.
Is BMI accurate?
It is a quick screening measure. It can't tell muscle from fat, so very muscular people can show as overweight. It isn't designed for children or pregnancy.
About this calculator
Formula and rules last checked 25 October 2026Written and tested by the CalcPenguin teamReport a problem
Sources: WHO expert consultation: BMI for Asian populations (The Lancet, 2004)