BMI Calculator
Find your body mass index (BMI) in seconds. Switch between imperial and metric units, enter your height and weight, and see your BMI, weight category, and the healthy weight range for your height — updated instantly, ready to export or share.
Body mass index
23.7
Normal
- Category
- Normal
- Healthy weight range
- 129–174 lbs
How to use the bmi calculator
- Choose imperial or metric units.
- Enter your height and weight.
- See your BMI and weight category, plus a healthy weight range for your height.
TipBMI is a quick screen, not a diagnosis — it doesn’t account for muscle, frame, or body composition.
How to use the BMI calculator
First pick your unit system. In imperial, enter your height as feet and inches and your weight in pounds; in metric, enter your height in centimetres and your weight in kilograms. The large readout shows your BMI to one decimal place, colour-coded to its weight category.
Below the readout you will see your category and the healthy weight range for your height — the weights that correspond to a BMI between 18.5 and 24.9 in the units you are using. Adjust any field and every figure recalculates live. Use the export buttons to save the result as CSV or Excel, print it to PDF, or copy a link that reopens the calculator with your exact numbers.
What your BMI means
Body mass index is a simple ratio of weight to height: in metric it is kilograms divided by height in metres squared, and the imperial formula (703 × pounds ÷ inches²) reproduces the same number. The standard adult bands are under 18.5 (underweight), 18.5–24.9 (normal), 25–29.9 (overweight), and 30 or above (obese).
BMI is a quick screening tool, not a diagnosis. It does not distinguish muscle from fat, so very muscular people can read as “overweight” while carrying little fat, and it does not account for age, sex, bone density, or where body fat sits. Treat your number as a starting point for a conversation, not a verdict — two people with the same BMI can have very different health.