How to use the BMI Calculator
- Choose metric or imperial units.
- Enter your height and weight.
- Tick "Asian cut-offs" if you are of South Asian or East Asian origin.
- Read your BMI, category and the healthy weight range for your height.
Formula used
| Category | WHO (adults) | Asian cut-offs |
|---|---|---|
| Underweight | Below 18.5 | Below 18.5 |
| Healthy weight | 18.5–24.9 | 18.5–22.9 |
| Overweight | 25–29.9 | 23–27.4 |
| Obesity | 30 and above | 27.5 and above |
Worked examples
| Height | Weight | BMI | WHO category |
|---|---|---|---|
| 160 cm | 50 kg | 19.5 | Healthy |
| 175 cm | 70 kg | 22.9 | Healthy (Asian: healthy) |
| 170 cm | 85 kg | 29.4 | Overweight (Asian: obesity) |
| 175 cm | 100 kg | 32.7 | Obesity |
What BMI does not tell you
BMI does not separate muscle from fat, so muscular people can show as overweight. It also does not show where fat sits. Waist size is a useful extra check: for most adults, aim for a waist less than half your height. For a better picture of body composition, try the Body Fat Calculator. To plan your meals, see your daily needs with the Calorie Calculator, or find a target with the Ideal Weight Calculator.
Medical note: this tool gives general estimates for healthy adults. It is not a diagnosis. Talk to a doctor or registered dietitian before making big changes, especially if you are pregnant, under 18, an athlete or living with a health condition.
Frequently asked questions
What is a healthy BMI?
For most adults, 18.5 to 24.9. For South Asian adults, health risks start to rise from 23, so many doctors use 18.5 to 22.9 as the healthy range.
Why are BMI cut-offs lower for Asians?
Research shows people of South Asian and East Asian origin tend to develop type 2 diabetes and heart disease at a lower BMI, so WHO and the NHS recommend lower thresholds for action.
Is BMI accurate for children?
No. Children and teenagers need BMI-for-age percentile charts, because healthy BMI changes as they grow.
How do I calculate BMI in feet and pounds?
Convert height to inches, then use BMI = 703 × weight in lb ÷ height in inches squared. Or switch this tool to imperial.
How often should I check my BMI?
Every few months is enough for most adults. Weigh yourself at the same time of day for consistent results.
Sources and references
Our team builds and tests every tool by hand, checks each formula against official sources (IRS, HMRC, the Income Tax Department of India, CBSE, NHS, WHO) and reviews pages whenever rules change. Last reviewed on . Spotted a mistake? Tell us.