Percentage calculator
Calculate percentages online, including percent of a number, percentage increase, and percentage decrease.
BMI calculator
Calculate your BMI online using height and weight. Get body mass index results with metric and imperial units.
How to use BMI calculator
Calculate your Body Mass Index (BMI) from height and weight using metric (cm/kg) or imperial (ft/in, lbs) units. BMI is a screening tool for weight categories — underweight, normal, overweight, and obese.
Understanding BMI results
- Under 18.5 — underweight
- 18.5–24.9 — normal weight
- 25–29.9 — overweight
- 30 and above — obese
Method: BMI is weight in kilograms divided by height in metres squared. Imperial inputs use weight in pounds ÷ height in inches² × 703. Adult category thresholds are general screening ranges and may not be appropriate for children, pregnancy, or highly muscular people.
BMI does not measure body fat directly. Talk to a healthcare provider for personal health advice.
BMI calculator FAQs
Is BMI calculator free?
BMI calculator is a free online tool on ReallyUseful.Tools. No account is required.
Does BMI calculator run in my browser?
BMI calculator is designed to run in your browser where supported, so files can stay on your device instead of being uploaded to a server.
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