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BMI
CALCULATOR

Calculate your Body Mass Index quickly and for free. BMI gives you a starting point for assessing your weight relative to your height — but it's only one data point. Read more below about what BMI can and cannot tell you.

CALCULATE YOUR BMI

WHAT IS BMI?

BMI — Body Mass Index — is a simple measure that relates your weight to your height. It was developed in the 19th century by the Belgian statistician Adolphe Quetelet and is used today by WHO as a quick screening tool for weight-related health risks.

The formula is simple: your weight in kilograms divided by your height in meters squared (kg/m²). The result places you in one of four categories.

BMI CATEGORIES

UnderweightBelow 18.5
Normal weight18.5 – 24.9
Overweight25.0 – 29.9
Obese30.0 or above

LIMITATIONS OF BMI

BMI is a useful screening tool, but it has important limitations you should know about:

  • !BMI doesn't distinguish between muscle mass and fat mass. A powerlifter with low body fat can have a BMI over 30.
  • !It doesn't account for fat distribution. Belly fat (visceral fat) is more harmful than fat on the hips, but BMI doesn't capture this difference.
  • !Age, gender, and ethnicity affect what constitutes a healthy BMI level. WHO's thresholds are general and don't apply to everyone.
  • !For children and the elderly, different reference ranges apply than for adults.

That's why BMI is best used as one data point in a broader assessment — not as the final verdict on your health. Try our body fat calculator for a more nuanced picture, or read about body recomposition — losing fat and building muscle simultaneously.

WANT HELP REACHING YOUR GOAL?

A number on a screen is a starting point — not a plan. Book a free consultation and let's talk about what actually works for you.

By Donovan Moloney, MSc Global Health, BSc Nutrition and Health