BMI Calculator
Check your Body Mass Index from your height and weight, and see the healthy weight range for your height.
Runs in your browser — your inputs never leave this device
Enter your height and weight to see your BMI and healthy weight range.
BMI is a general screening measure for adults. It does not account for muscle mass, bone density, age or body composition, and it is not a diagnosis — talk to a healthcare professional about your individual health.
Related tools
How to use the BMI Calculator
- Choose Metric (cm and kg) or Imperial (feet, inches and pounds) using the toggle at the top.
- Enter your height and weight — the result updates live as you type.
- Read your BMI value, its category, and where the marker sits on the scale bar.
- Check the healthy weight range shown for your height to see the 18.5–24.9 BMI band in your units.
Frequently asked questions
How is BMI calculated?
BMI = weight in kilograms divided by height in metres squared (kg/m²). In imperial units the equivalent formula is BMI = 703 × pounds ÷ inches². Both give the same result for the same person.
Are my height and weight uploaded anywhere?
No. This calculator runs entirely in your browser — your inputs are never uploaded, logged or stored. Everything is calculated locally on your device.
What are the standard BMI categories?
For adults: Underweight is below 18.5, Healthy is 18.5 to 24.9, Overweight is 25 to 29.9, and Obese is 30 or above. These are the widely used WHO ranges.
Is BMI accurate for athletes or muscular people?
BMI can overestimate body fat in people with a lot of muscle, because muscle weighs more than fat for the same volume. It is a useful general screening tool, not a complete measure of health.
Does BMI apply to children?
Not directly. For children and teenagers, BMI is interpreted using age- and sex-specific percentile charts. This calculator uses the adult categories.