Instantly check your BMI in metric or imperial units
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Your BMI Result
BMI Scale
Note: BMI is a screening tool, not a diagnostic measure. It does not account for muscle mass, bone density, age, or sex. Consult a healthcare professional for a full health assessment.
Our free BMI calculator helps you determine your Body Mass Index in seconds. Simply enter your height and weight using either metric (centimetres and kilograms) or imperial (feet, inches, and pounds) units. Get your BMI score instantly along with your weight category — from underweight to obesity class III — plus the healthy weight range for your height.
A BMI between 18.5 and 24.9 is considered normal or healthy weight for most adults. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above falls into the obesity range.
BMI is a useful population-level screening tool but has limitations for individuals. It does not account for muscle mass, bone density, age, sex, or ethnic background. Athletes may have a high BMI due to muscle, not fat. Always consult a doctor for a full assessment.
BMI equals weight in kilograms divided by the square of height in metres (kg/m²). In imperial units, the formula is (weight in lbs × 703) ÷ (height in inches)², which our calculator handles automatically when you select imperial mode.
The healthy weight range is calculated by finding the weights that correspond to a BMI of 18.5 (lower bound) and 24.9 (upper bound) for your specific height. Our calculator shows this range in your chosen unit — kilograms or pounds.