Calculate your Body Mass Index from height and weight. Supports metric (cm/kg) and imperial (ft/in/lb) inputs.
Enter your height and weight in metric or imperial units to instantly calculate your BMI. The result shows your BMI value and the standard weight category (Underweight, Normal, Overweight, or Obese) on a colour-coded scale. Note that BMI is a population-level screening tool and does not account for muscle mass, bone density, or body composition.
Choose Metric or Imperial using the toggle. Enter your height and weight — your BMI and weight category update immediately. The coloured scale shows where your BMI falls relative to the standard ranges.
The WHO defines a BMI of 18.5–24.9 as 'Normal weight'. Below 18.5 is Underweight, 25–29.9 is Overweight, and 30 or above is Obese.
Not always. BMI uses weight without distinguishing between fat and muscle. Athletes with high muscle mass often score as Overweight despite having low body fat. BMI is a screening tool, not a diagnostic one.
Yes. For people under 18, BMI is interpreted differently using age- and sex-specific percentile charts. This calculator uses adult BMI thresholds only.
This tool runs entirely in your browser. Nothing you type or paste is sent to any server — all processing happens locally on your device.