BMI Calculator UK

Understanding Your BMI Score

This calculator is designed specifically for UK users, allowing you to input your weight in Stones and Pounds and height in Feet and Inches, whilst also supporting standard metric inputs (kg and cm).

The Body Mass Index (BMI) is widely used by the NHS and medical professionals as a basic screening tool to determine if an individual falls into a healthy weight range.

Important Considerations:

Age and Gender: The standard BMI formula applies to both men and women over the age of 18. It is not suitable for children or pregnant women.
Muscle Mass: Muscle weighs more than fat. Athletes and very muscular people might have a high BMI without having excessive body fat.
Ethnicity: Some ethnic groups may have a higher risk of health problems at a lower BMI. For example, adults of South Asian origin may have a higher risk of health problems at a BMI of 23 or more.

Frequently Asked Questions

What is BMI?

Body Mass Index (BMI) is a measure that uses your height and weight to work out if your weight is healthy. The BMI calculation divides an adult's weight in kilograms by their height in metres squared.

What are the NHS BMI categories?

According to the UK NHS guidelines: A BMI below 18.5 is considered 'underweight'. A BMI of 18.5 to 24.9 is considered a 'healthy weight'. A BMI of 25 to 29.9 is considered 'overweight'. A BMI of 30 or above is considered 'obese'.

Is BMI an accurate measure of health?

BMI can be a useful indicator of whether you're a healthy weight, but it's not perfect. It cannot tell the difference between excess fat, muscle, or bone. For example, highly muscular adults and athletes may be classed as 'overweight' or 'obese' even though their body fat is low.

How do I measure my height and weight accurately?

For the most accurate results, weigh yourself first thing in the morning without shoes and wearing light clothing. Measure your height standing straight against a wall, without shoes, keeping your heels, back, and head touching the wall.