Body Mass Index (BMI) is one of the most common health screening numbers, but it is often misunderstood. This guide explains what BMI is, how to calculate it, what the ranges mean and where the measure falls short.
What is BMI?
BMI is a simple ratio of your weight to your height. It gives a quick estimate of whether you are in a healthy weight range for your height. Calculate yours instantly with our BMI Calculator.
BMI ranges
- Below 18.5 — underweight
- 18.5 to 24.9 — healthy weight
- 25 to 29.9 — overweight
- 30 and above — obese
The limits of BMI
BMI does not distinguish between muscle and fat, so very muscular people can read as “overweight” despite being lean. It also does not account for age, sex or where fat is stored. Treat it as a general guide, not a diagnosis.
BMI vs BMR
BMI estimates weight status, while your Basal Metabolic Rate (BMR) estimates how many calories your body burns at rest. If you are planning your diet, the BMR Calculator is a useful companion for working out daily calorie needs.
Frequently asked questions
Is BMI accurate? It is a useful population-level screening tool but a rough guide for individuals. Always consult a healthcare professional for personalised advice.
What is a healthy BMI? Generally a BMI between 18.5 and 24.9 is considered healthy for most adults.