Calculate your Body Mass Index instantly with metric or imperial units. Free, private, no signup — healthy weight range shown in seconds.
Select Metric (kg and cm) or Imperial (lbs, feet, and inches) depending on your preference.
Type your values and BMI calculates instantly as you type.
See your BMI number and which WHO health category you fall into.
According to WHO guidelines, a BMI of 18.5–24.9 is considered normal and healthy for most adults. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is classified as obese.
BMI doesn't distinguish between muscle and fat. Athletes and bodybuilders often have a high BMI despite very low body fat. For a complete health assessment, consult a doctor who can measure body composition directly.
BMI = weight (kg) ÷ height² (m). In imperial: BMI = (weight in lbs ÷ height in inches²) × 703. This calculator handles both metric and imperial automatically.
Standard BMI ranges are for adults 20 and older. For children and teenagers, BMI is interpreted using age- and sex-specific growth charts. This tool is intended for adult use.
A BMI of 30 or above is classified as obese. Class 1 (30–34.9), Class 2 (35–39.9), and Class 3 — also called morbid obesity — is 40 and above.
Yes. To find a target weight for a normal BMI (18.5–24.9): target weight = desired BMI × height (m)². However, consult a healthcare professional for a safe, personalized weight management plan.
No. All calculations happen locally in your browser. Nothing is sent to any server.