Free BMI Calculator
Enter your height and weight to get your Body Mass Index in seconds. The tool supports metric and imperial units, shows your category — underweight, normal, overweight or obese — and marks your result on a visual scale with your healthy weight range.
How to Use the BMI Calculator
- Choose Metric or Imperial units.
- Enter your height and weight.
- Click Calculate BMI to see your index and category on the scale.
Features
One-tap switching between centimeters/kilograms and inches/pounds, instant BMI computation, WHO-based category classification, a visual scale marker, and the healthy weight range for your exact height.
Benefits & Use Cases
Useful as a quick screening number before a doctor’s visit, for tracking weight-loss progress, or for health forms that ask for BMI. The healthy-range readout tells you which weight band to aim for.
Tips
Measure height without shoes and weight in the morning for the most consistent readings. Remember that BMI does not distinguish muscle from fat — athletes should pair it with a body-fat estimate.
Frequently Asked Questions
What is a healthy BMI?
A BMI between 18.5 and 24.9 is classified as normal weight by the World Health Organization.
How is BMI calculated?
Weight in kilograms divided by height in meters squared. In imperial mode the tool converts your entries first, then applies the same formula.
Is BMI accurate for muscular people?
Not always — muscle weighs more than fat, so very muscular people can score as overweight. Use BMI as a screening tool, not a diagnosis.
Should children use this calculator?
BMI is interpreted differently for children using age-and-sex percentiles, so this adult calculator is not suitable for kids — ask a pediatrician instead.
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