BMI Calculator
Your Body Mass Index in metric or imperial units, your WHO category on a visual scale, and the healthy weight range for your exact height.
BMI is a screening measure, not a diagnosis — it doesn't distinguish muscle from fat and can mislead for athletes, older adults, and some ethnic groups. Talk to a healthcare professional about what's right for you.
Frequently asked questions
How is BMI calculated?
BMI = weight (kg) ÷ height (m)². For example, 75 kg at 1.75 m tall gives 75 ÷ 3.06 = 24.5 — in the healthy range. In imperial units the formula is 703 × weight (lb) ÷ height (in)².
What is a healthy BMI?
The WHO defines 18.5–24.9 as the healthy range. Below 18.5 is underweight; 25–29.9 is overweight; 30 and above is classed as obesity (classes I–III at 30, 35, and 40). This calculator translates the healthy range into kilograms for your exact height.
Is BMI accurate?
It's a useful population-level screening tool, not an individual diagnosis. BMI can't tell muscle from fat, so muscular people read high and people who've lost muscle can read deceptively normal. Waist measurement and body composition give a fuller picture — and a clinician beats any formula.