BMI Calculator
Body mass index from height and weight, with WHO or Asian-Indian cut-offs and the healthy weight for your height.
Your BMI
- Healthy weight for your height
- 50.4 kg – 67.8 kg
- Where you are
- In the healthy range
- BMI Prime
- 0.91
- Underweightunder 18.5
- Healthy weight18.5 – 24.9
- Overweight25 – 29.9
- Obesity class I30 – 34.9
- Obesity class II35 – 39.9
- Obesity class III40 and over
- For adults. BMI does not tell muscle from fat, and does not apply in pregnancy or to children, who are measured on growth charts.
You
How is this calculated?
BMI = weight (kg) ÷ height (m)² · BMI Prime = BMI ÷ 25 (WHO) or ÷ 23 (Asian-Indian)Runs in your browser — nothing you enter leaves this device.
A general estimate. BMI and calorie formulas don't account for body composition, pregnancy, or medical conditions. Talk to a doctor before changing diet or exercise.
About this tool
What it does
Body mass index (BMI) compares your weight with your height, so people of different heights can be read on one scale. This calculator gives your BMI, the band it falls in, the weight range that counts as healthy for your height, and how far you are from that range. You can read the bands by the World Health Organization’s cut-offs or by the lower cut-offs used for Asian and Indian adults, whose risk of diabetes and heart disease rises at a lower BMI.
How to use it
- Choose centimetres and kilograms, or feet, inches and pounds.
- Set your height and your weight with the sliders or the number boxes.
- Pick the cut-offs: WHO, or Asian / Indian if that is your background.
- Read your BMI, its band, and the healthy weight range for your height.
Limits and your data
- BMI is for adults. Children and teenagers are measured against growth charts for their age and sex, which this calculator does not do.
- It cannot tell muscle from fat: a muscular athlete can read as overweight, and an older person who has lost muscle can read as healthy while carrying too much fat.
- It does not apply in pregnancy, and it says nothing about where fat sits. Waist size adds that: a waist over half your height is a common warning sign.
- Bands are compared at one decimal place, as BMI is reported, so 24.96 reads 25.0 and counts as overweight on the WHO scale.
- Your height and weight stay in this page. They are not saved, not sent anywhere and, unlike most calculators on this site, not put in the page address, because body measurements are personal. Reloading the page starts again from the example values.
Questions
Why are there two sets of cut-offs?
In 2004 a WHO expert consultation found that many Asian populations have a higher risk of type 2 diabetes and heart disease at BMIs below 25. India’s consensus guidelines (2009) adopted lower cut-offs for Indian adults: overweight from 23 and obesity from 25. The WHO scale (overweight from 25, obesity from 30) remains the international standard, so both are offered.
What is a healthy BMI?
From 18.5 to 24.9 on the WHO scale, or 18.5 to 22.9 on the Asian-Indian scale. The calculator turns that into kilograms or pounds for your height, which is usually the more useful number.
What is BMI Prime?
Your BMI divided by the top of the healthy band. A BMI Prime of 1.00 is the edge of overweight, 0.90 is 10% under it and 1.20 is 20% over. It makes the distance from the limit easy to read.
I am muscular. Should I trust my BMI?
Less than most people should. Because muscle is dense, BMI overstates fat for strength athletes. A body-fat measurement or your waist size will tell you more.
How accurate is the healthy weight range?
It is exact for the BMI limits at your height, but the limits themselves are population averages. Your doctor may set a different target for you.