Enter your height and weight, in metric or imperial units, to get your body mass index, category and a healthy weight range.
Understanding the bmi calculation
BMI is a quick screening number that relates weight to height. Enter your measurements and this calculator returns your BMI, the standard category, and the weight range considered healthy for your height.
BMI is a general guide, not a diagnosis — it doesn’t account for muscle, build or body composition, so treat it as one data point among many.
How to use it
- Choose metric or imperial units.
- Enter your height and weight.
- Read your BMI, category and healthy weight range.
Formula reference
metric: BMI = weight(kg) ÷ height(m)²
imperial: BMI = 703 × weight(lb) ÷ height(in)²
Try it with these numbers
Worked through, a height of 175, weight of 70 produces a BMI of 22.9. Underneath, Category comes out at Healthy weight and Healthy weight range at 56.7–76.3 kg. Change any field and every figure updates as you type.
Questions people ask about this
What is a healthy BMI?
The standard ranges are: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, and 30+ obese.
Is BMI accurate for everyone?
Not perfectly — it doesn’t distinguish muscle from fat, so very muscular people can read high. It’s a screening tool, not a diagnosis.
Should I see a doctor about my BMI?
For personalised advice about your weight and health, talk to a qualified healthcare professional rather than relying on BMI alone.