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BMI Calculator
Enter your height and weight to get your body mass index, your WHO category, and the healthy weight range for your height. Metric or imperial — instant, no sign-up.
What BMI does and doesn’t tell you
BMI is a fast screen that relates your weight to your height. It’s useful for spotting a trend across weeks, but it can’t see body composition — a muscular athlete and a sedentary person can share a BMI. Treat it as one data point, not a verdict, and pair it with how your clothes fit and how you feel.
Questions
- How is BMI calculated?
- BMI = weight in kilograms divided by height in metres squared (kg/m²). In imperial units it is 703 × weight in pounds ÷ height in inches squared. This calculator handles both for you.
- What are the BMI categories?
- The WHO ranges are: under 18.5 underweight, 18.5–24.9 normal weight, 25–29.9 overweight, and 30 or above obesity. The healthy weight range shown is the weight that puts your BMI between 18.5 and 24.9.
- Is BMI accurate?
- BMI is a quick population-level screen, not a diagnosis. It does not distinguish muscle from fat, so very muscular people can read “overweight” while being lean. Use it as one signal alongside how you look, feel, and measure.
- How do I change my BMI?
- BMI moves as your weight changes, which comes down to a consistent calorie balance over weeks. The hard part is staying consistent with tracking — which is exactly what Calorie Puzzle is built to make effortless.
This calculator gives a general fitness estimate, not medical advice. If you have a medical condition or any history of disordered eating, please don’t use a weight tool — talk to a doctor or qualified professional.