What is BMI?
Body Mass Index (BMI) is a simple number that compares your weight with your height. Doctors use it as a first check for whether someone might be underweight, at a healthy weight, overweight or obese. This BMI calculator uses the Asian-Indian cut-offs from India's national consensus guidelines by default, because research shows that South Asians face higher risks of diabetes and heart disease at lower BMIs than Europeans. You can switch to the WHO global ranges with one tap.
How to use it
- Choose metric (cm and kg) or feet-inches and pounds.
- Enter your height and weight.
- See your BMI, category, healthy weight range for your height and how many kilos to gain or lose to reach it.
BMI formula
BMI = weight (kg) ÷ [height (m)]²
In pounds and inches: BMI = 703 × weight (lb) ÷ [height (in)]².
Example
A person 170 cm tall weighing 68 kg has a BMI of 68 ÷ (1.70 × 1.70) =23.5. By WHO standards that's normal, but under Indian guidelines it's in the overweight range (23–24.9). Their healthy weight range is about 53.5–66.4 kg, so losing around 1.6 kg would bring them into it.
BMI categories
| Category | India / Asian | WHO global |
|---|---|---|
| Underweight | Below 18.5 | Below 18.5 |
| Normal | 18.5 – 22.9 | 18.5 – 24.9 |
| Overweight | 23 – 24.9 | 25 – 29.9 |
| Obese | 25 and above | 30 and above |
Health disclaimer: This tool gives general estimates for information only and is not medical advice, diagnosis or treatment. Please consult a qualified doctor about your health. Read the full disclaimer.