SuperCalc

Calculate Body Mass Index

Calculating your Body Mass Index is simple: divide your weight in kilograms by your height in meters squared. Or use this calculator — enter your measurements and get your BMI instantly, along with a visual gauge, WHO category, healthy weight range, and BMI Prime. Below, we explain the formula step by step in both metric and imperial units.

BMI Calculator

Enter your height and weight to calculate your Body Mass Index.

cm
kg

BMI Categories

WHO classification of Body Mass Index ranges.

CategoryBMI Range
Underweight
< 18.5
Normal
18.5 – 24.9
Overweight
25 – 29.9
Obese I
30 – 34.9
Obese II
35 – 39.9
Obese III
40+

Frequently Asked Questions

How do I calculate BMI manually?
Step 1: Measure your height in meters (cm / 100). Step 2: Square it (multiply by itself). Step 3: Divide your weight in kg by that number. Example: 72 kg, 1.75 m. 1.75 x 1.75 = 3.0625. 72 / 3.0625 = 23.5. Your BMI is 23.5.
Can I calculate BMI in pounds and inches?
Yes. Use: BMI = (weight in lbs / height in inches^2) x 703. Example: 160 lbs, 5'7" (67 in). 67 x 67 = 4489. 160 / 4489 = 0.03563. 0.03563 x 703 = 25.1. Or just toggle to imperial in the calculator above.
What is BMI Prime?
BMI Prime is your BMI divided by 25 (the upper limit of normal). A BMI Prime of 1.0 means you are exactly at the overweight threshold. Below 1.0 = within healthy range. Above 1.0 = above it. For example, a BMI of 22 gives BMI Prime of 0.88 — you're 12% below the overweight line.

Medical disclaimer: BMI is a screening tool, not a medical diagnosis. It does not measure body fat directly and does not account for muscle mass, bone density, age, sex, or ethnicity. Consult a healthcare provider for personalized health advice.

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