BMI calculator
This BMI calculator works out your body mass index (BMI) from your height and weight, and shows your weight category on the WHO scale and on the lower cut-offs used for Asian adults. BMI is your weight in kilograms divided by your height in metres squared.
Your results
Fill in the form and select Calculate. Your results show here.
WHO BMI categories for adults
| Category | BMI |
|---|---|
| Underweight | Below 18.5 |
| Normal weight | 18.5-24.9 |
| Overweight | 25.0-29.9 |
| Obesity | 30.0 or more |
BMI categories for Asian adults
Used by Malaysia's Ministry of Health clinical practice guideline on obesity.
| Category | BMI |
|---|---|
| Underweight | Below 18.5 |
| Normal weight | 18.5-22.9 |
| Overweight | 23.0-27.4 |
| Obesity | 27.5 or more |
How this is calculated
The BMI formula
BMI is weight divided by height squared. In imperial units, the calculator converts pounds to kilograms and feet and inches to centimetres first.
BMI = weight (kg) ÷ height (m)²
Why there are Asian cut-offs
A WHO expert consultation in 2004 found that many Asian people have a high risk of type 2 diabetes and heart disease at BMIs below the WHO overweight cut-off of 25. It kept the WHO categories as the international standard and named extra action points at 23, 27.5, 32.5 and 37.5. Malaysia's clinical practice guideline on obesity (2023) uses 23 for overweight and 27.5 for obesity in adults.
What BMI does not show
BMI cannot tell muscle from fat, so a muscular person can get a high BMI. It also does not show where fat sits on the body, and it can be less accurate for older adults. For children and teenagers, the WHO uses BMI-for-age growth charts instead.
Example
A person who weighs 70 kg and is 1.75 m tall has a BMI of 70 ÷ (1.75 × 1.75) = 22.9. That is normal weight on both scales.
Sources
- World Health Organization. Obesity and overweight (fact sheet).
- World Health Organization, Global Health Observatory. Body mass index (BMI).
- WHO Expert Consultation. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. The Lancet, 2004;363(9403):157-163.
- Ministry of Health Malaysia. Clinical Practice Guidelines: Management of Obesity, 2nd edition, 2023 (Table 2-1).
We checked these sources on 16 October 2026.
Frequently asked questions
What is a healthy BMI?
On the WHO scale, a BMI from 18.5 to 24.9 is normal weight for adults. For Asian adults, Malaysia's Ministry of Health guideline uses a lower range: 18.5 to 22.9.
What BMI is overweight for Asians?
With the Asian cut-offs, a BMI of 23.0 to 27.4 is overweight (pre-obese) and 27.5 or more is obesity. These are the cut-offs in Malaysia's clinical practice guideline on obesity. The WHO scale uses 25 for overweight and 30 for obesity.
How do I calculate my BMI?
Divide your weight in kilograms by your height in metres, squared. For example, 70 kg at 1.75 m is 70 ÷ (1.75 × 1.75) = 22.9. The calculator on this page does the maths for you, in metric or imperial units.
Is BMI accurate?
BMI is a quick screening number, not a diagnosis. It does not separate muscle from fat or show where fat is stored. Malaysia's guideline also recommends measuring waist circumference along with BMI.
Can I use this BMI calculator for children?
No. The categories on this page are for adults aged 18 and over. For children and teenagers, the WHO defines overweight and obesity with BMI-for-age growth charts.
Get your daily calorie target in Nibbs
BMI shows where your weight sits. For a daily calorie and macro target, answer a few questions in Nibbs. Then log meals with a photo, a typed description or a barcode scan.