BMI Calculator
Calculate your Body Mass Index from your height and weight, see your category, and find the healthy weight range for your height.
BMI is a quick screen, not a diagnosis. It doesn't distinguish muscle from fat, so very muscular people may read high. Not medical advice.
How to use this calculator
Enter your height in feet and inches and your weight in pounds. The calculator shows your BMI, the standard category, and the weight range considered healthy for your height.
What BMI means
Body Mass Index estimates whether your weight is in a healthy range relative to your height. It's widely used because it's quick and requires only two measurements, but it doesn't directly measure body fat or fitness.
Worked example
Someone 5'10" weighing 170 lb has a BMI of about 24.4 — within the normal range, where the healthy weight band is roughly 129–173 lb.
The formula
BMI = 703 × weight(lb) ÷ height(in)²
Frequently asked questions
How is BMI calculated?
BMI is weight divided by height squared. In US units the formula is 703 × weight(lb) ÷ height(in)². For example, 170 lb at 70 in is 703 × 170 ÷ 4900 ≈ 24.4.
What is a healthy BMI?
Standard categories are: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, and 30+ obese. The calculator also shows the healthy weight range for your height.
Is BMI accurate?
BMI is a useful population screen but a blunt individual measure. It doesn't separate muscle from fat, so athletes can read 'overweight,' and it doesn't capture where fat is stored. Use it as one data point.
What's a better measure of body fat?
Waist circumference, waist-to-height ratio, or a body fat estimate give more insight into health risk. Try our body fat calculator for a tape-based estimate.