Personal health instrument

Know your number.

Enter your height and weight in whichever unit system you use. Your BMI is calculated instantly, on this page — nothing is sent anywhere.

ft in
lb
1218.5253042

BMICategory
Below 18.5Underweight
18.5 – 24.9Normal weight
25.0 – 29.9Overweight
30.0 and aboveObese

What BMI does and doesn't tell you

Body Mass Index is a simple ratio of weight to height. It's a useful screening number at a population level, but it doesn't distinguish muscle from fat, and doesn't account for age, sex, bone structure, ethnicity, or pregnancy. Two people with the same BMI can have very different body compositions and health profiles.

Use this calculator as a starting point for a conversation, not a diagnosis. For a fuller picture of your health, talk to a doctor or a registered dietitian — see our medical disclaimer for more on this.