BMI Calculator
Free BMI calculator. Find your Body Mass Index and weight category in metric or imperial units, plus the healthy weight range for your height.
Your Measurements
Body Mass Index
22.9
Details
How It Works
Choose your units
Switch between metric (kilograms and centimetres) or imperial (pounds, feet and inches).
Enter weight and height
Type your current weight and height. The result updates instantly as you type.
Read your result
See your BMI value, the weight category it falls in, and the healthy weight range for your height.
Body Mass Index (BMI) is a simple, widely used measure that relates your weight to your height to estimate whether you are in a healthy weight range. It was designed as a quick population-level screening tool and gives a single number that places you into one of four broad categories: underweight, normal, overweight or obese.
Because BMI uses only height and weight, it cannot tell the difference between muscle and fat, so athletes and very muscular people may register a high BMI without excess fat. Use this calculator to get a quick reference point and a healthy weight range for your height, then talk to a healthcare professional for a fuller picture that includes body composition, waist measurement and overall health.
Frequently Asked Questions
How is BMI calculated?
BMI is weight divided by height squared. In metric units, BMI = kg ÷ (metres)². In imperial units, BMI = 703 × pounds ÷ (inches)². The same value is then matched to a standard weight category.
What are the BMI categories?
A BMI below 18.5 is considered underweight, 18.5 to 24.9 is a normal (healthy) weight, 25 to 29.9 is overweight, and 30 or above is classed as obese. These ranges apply to most adults aged 20 and over.
What is a healthy weight for my height?
A BMI between 18.5 and 24.9 is generally considered healthy. This calculator converts that range back into a weight range for your specific height, so you can see the lower and upper healthy weight in your chosen units.
Is BMI always accurate?
BMI is a useful general screening tool but it does not measure body fat directly and can misclassify very muscular people or older adults. Results are estimates for general information only and are not medical advice — consult a healthcare professional for personal guidance.
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