BMI Calculator
Calculate BMI with gender and age in metric or imperial units. Includes BMI Prime, Ponderal Index, estimated body fat, and healthy weight range.
A body-composition calculator that goes beyond a single number. Enter your gender, age, height, and weight in metric (cm, kg) or imperial (ft/in, lbs) units to get your standard BMI and WHO category, plus BMI Prime, the Ponderal Index, an estimated body fat percentage from the Deurenberg formula, and the healthy weight range for your height. Every method is computed locally in your browser.
Body Mass Index (BMI) is a widely used screening metric that estimates body fat based on your height and weight. It's a quick way to see whether your weight falls in a range that, on average, is associated with lower health risk. This BMI calculator accepts both metric (cm and kg) and imperial (feet/inches and pounds) units, and returns your BMI, category, and a visual gauge with color-coded bands.
Alongside your BMI, the tool shows the healthy weight range for your specific height - useful if you're setting a goal. Keep in mind BMI is a blunt instrument: it doesn't distinguish muscle from fat, and it wasn't designed for elite athletes, pregnant women, or children. Treat the result as one data point among many, and consult a healthcare provider for a full assessment.
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Choose your units
Toggle between Metric (centimeters and kilograms) and Imperial (feet/inches and pounds) based on what's most natural for you.
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Enter height and weight
Type your height and weight in the selected units. The calculator updates instantly as you type.
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Read your result
See your BMI, category, visual gauge position, and the healthy weight range for your height. Use it as a screening starting point, not a diagnosis.
Track progress
Recalculate periodically to see how your BMI changes as you progress toward a fitness or weight goal.
Set a healthy weight target
Use the healthy weight range as a reference point when setting realistic targets for your height.
Quick health screening
Get a fast, private indicator of whether your weight falls in a commonly accepted healthy range.
What is the BMI formula?
BMI = weight (kg) / height (m)². For imperial units the calculator converts inches to meters (× 0.0254) and pounds to kilograms (× 0.453592) before applying the formula.
What are the BMI categories?
Underweight: below 18.5. Normal: 18.5 to 24.9. Overweight: 25 to 29.9. Obese: 30 and above. These are the standard adult categories used by the WHO.
Is BMI accurate for everyone?
No. BMI doesn't account for muscle mass, bone density, body composition, age, sex, or ethnicity. Athletes, bodybuilders, and very muscular people often register as overweight or obese despite having low body fat.
Should I use BMI for children?
No - this tool is for adults. Children and teens use age- and sex-specific BMI percentiles instead. Consult a pediatrician for child BMI assessments.
Is my data private?
Yes. All calculations happen entirely in your browser. Nothing is uploaded or stored anywhere.