BMI Calculator - Body Mass Index
If you're searching for how to calculate BMI (Body mass index), this BMI calculator is what you need. Enter the height and weight, and the BMI calc will provide the result immediately, conveniently allowing you to enter height and weight in units of your choice.
🙋 Knowing how to calculate your BMI can give you insight into your level of health, but there's another mass-height measure that could give you an even better insight, called body surface area (BSA). Your BSA is a predictor of coronary artery calcium, a severe medical concern that BMI cannot predict. BSA is also a better indicator of metabolic rate than body weight. Learn more about it in our BSA calculator.
What is BMI?
The BMI is a quantity that doctors and nutritionists use to determine if a person is overweight or under-weight and to what extent. We calculate it by dividing the person's mass (in kilograms) by the square of their height (in meters).
How do I calculate BMI? BMI formula
To calculate your BMI with your mass in kilograms and height in meters, use the following formula:
BMI = Masskg/Heightm2
- BMI — Body mass index;
- Masskg — your mass in kilograms (kg); and
- Heightm — your height in meters (m);
If you only know the mass in pounds and the height in inches, multiply the formula by 703:
BMI = 703 × Masslb/Heightin2
- Masslb — your mass in pounds (lb); and
- Heightin — your height in inches (in);
What is BMI Prime?
The BMI Prime is a nifty modification to our own BMI calculator. It's a decimal number where 1.0 is the upper limit to the "normal BMI" range. If your BMI Prime is more than 1, then you have some weight to lose.
As the BMI upper limit before reaching overweight is 25, we calculate BMI Prime by dividing the conventional BMI by 25:
BMI Prime = BMI/25