BMI Calculator UK

This BMI calculator determines your body mass index, health category, and health risk based on height and weight.

Unit Type:

ft
in
cm
lb
kg
kg/m2
Buy me a coffee

How Does the BMI Calculator Work?

  1. Select the preferred unit type.
  2. Enter your height in either feet and inches or in centimeters.
  3. Enter your weight in either pounds or kilograms.
  4. After inputting your height and weight, press the "Calculate" button.
  5. The tool will return your body mass index (BMI) and its category. It also shows your health risk according to your BMI score.
  6. For new BMI calculations, press the 'Reset' button.

BMI Introduction

Body Mass Index (BMI) measures a person's body fat based on height and weight. It's a widely used metric for assessing a person's body weight relative to height.

By knowing your BMI, you can better understand your health status and make a change in your lifestyle, diet, and physical activity.

How is BMI Calculated?

The BMI is calculated using the following formulas:

Metric System:

BMI =  
Weight (kg)
[Height (m)]2

Imperial System:

BMI =  
Weight (lbs)
[Height (in)]2
   × 703

BMI Categories

Here's a detailed breakdown of BMI used for men and women, aged 20 or older.

BMI Category BMI Range (kg/m2) Health Risk
Underweight Below 18.5 Malnutrition Risk
Normal Weight 18.5 - 24.9 Low Risk
Overweight 25 - 29.9 Enchanced Risk
Moderately Obese 30 - 34.9 Medium Risk
Severely Obese 35 - 39.9 High Risk
Very Severely Obese 40 or Higher Very High Risk

BMI categories for kids or children (Age < 20).

BMI Category BMI Percentile (kg/m2) Health Risk
Underweight Less than 5th percentile Malnutrition Risk
Normal Weight 5th percentile to less than 85th percentile Low Risk
Overweight 85th percentile to less than 95th percentile Enchanced Risk
Obese 95th percentile and greater High Risk

BMI Chart

BMI Chart