This BMI calculator estimates body mass index from height and weight, then maps the result to common BMI categories used in everyday health screening.
Health
BMI Calculator — Body Mass Index
Calculate body mass index and common weight categories from height and weight.
Calculator
About this calculator
Formula notes
BMI = weight (kg) / [height (m)]^2. If you enter imperial units, the calculator converts them before applying the formula.
Worked examples
- Example: 70 kg and 1.75 m give BMI = 70 / 1.75^2 ~ 22.9, which usually falls in the normal range.
- At 95 kg and 1.80 m, BMI is 95 / 1.80^2 = 29.3; the number is a screening category and does not show how much weight is muscle or fat.
How to use it
- Enter your height and weight.
- Confirm the units match what you measured.
- Read the BMI value and the matching category.
Frequently asked questions
Is BMI a diagnosis?
No. BMI is a screening estimate. Muscle mass, age, sex, and body composition can change how the number should be interpreted.
Which units can I use?
Use metric or imperial inputs. The page converts values before calculating BMI.
Limits and interpretation
- Adult BMI categories do not directly apply to children and teenagers, who use age- and sex-specific growth references.
- BMI does not measure body composition and can misclassify people with high muscularity, pregnancy, oedema, or unusual body proportions.