ZapKit

BMI Calculator

Enter your height and weight to get your body mass index, what it means on the Asian cut-offs recommended for Indians or the international WHO scale, and the weight range that counts as healthy for your height.

What is BMI?

Body mass index (BMI) compares your weight with your height to give one number that doctors use to screen for underweight, overweight and obesity in adults. It's quick, needs no equipment, and higher values are linked with a higher risk of diabetes, high blood pressure and heart disease across large groups of people.

This calculator works in metric or imperial units, shows your BMI on a colour scale, and gives the healthy weight range for your height. You can switch between the lower Asian cut-offs, which suit people of Indian and other Asian descent, and the international WHO categories.

How to use the BMI Calculator

  1. 1.Choose units

    Centimetres and kilograms, or feet, inches and pounds.

  2. 2.Enter height and weight

    Your BMI and category update as you type.

  3. 3.Pick the scale

    Indian/Asian cut-offs are the default; switch to WHO international to compare.

Example: 170 cm and 70 kg

One person, two sets of categories:

BMI
70 ÷ 1.70² = 24.2
WHO category
Healthy weight (18.5–24.9)
Asian category
Overweight (23–24.9)
Healthy range, WHO
about 53.5–72 kg
Healthy range, Asian
about 53.5–66.4 kg

BMI = weight (kg) ÷ height (m)²

The same 24.2 is healthy on the international scale but overweight on the Asian one, about 3.5 kg above its healthy range.

Why Indians use lower cut-offs

Studies show that South Asians develop type 2 diabetes and heart disease at lower BMIs than Europeans, because they tend to carry more body fat, especially around the waist, at the same weight. A WHO expert consultation in 2004 and Indian consensus guidelines in 2009 therefore suggest treating 23 as the start of overweight and 25 as obesity, instead of 25 and 30.

Waist size adds useful information: above about 90 cm for Indian men or 80 cm for women suggests extra risk even at a normal BMI.

Frequently asked questions

What is a normal BMI for Indians?

18.5 to 22.9 on the Asian cut-offs. 23 to 24.9 counts as overweight and 25 or more as obese.

Is BMI accurate?

It's a quick screening number, not a diagnosis. It can't tell muscle from fat, so athletes may score high, and it doesn't show where fat is stored.

Can children use this BMI calculator?

No. Children and teenagers are assessed with growth charts for their age and sex.

How do I calculate BMI by hand?

Divide your weight in kilograms by your height in metres, squared. 70 ÷ (1.7 × 1.7) = 24.2.

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