BMI Calculator – Check Body Mass Index

kg
cm
Your BMI Score
22.9
Normal Weight
0 18.5 25 30 40+
Ideal Weight Range: 56.7 kg - 76.6 kg
Category BMI Range
Underweight Less than 18.5
Normal Weight 18.5 - 24.9
Overweight 25 - 29.9
Obese 30 or greater

Body Mass Index (BMI) is a simple medical screening tool that uses height and weight to estimate body fat. It helps categorize whether a person is underweight, normal weight, overweight, or obese.

BMI Calculation Formula

Metric Units (kg & cm):
BMI = weight(kg) / [height(m) × height(m)]

Standard/US Units (lbs & inches):
BMI = 703 × weight(lbs) / [height(in) × height(in)]

Limitations of BMI

While BMI is a widely used and useful indicator of healthy body weight, it does have limitations. It does not distinguish between muscle mass and fat mass. Highly muscular athletes, for instance, may have a high BMI but very low body fat percentages. It also does not account for age or gender differences.

Worked Example

Example assumptions
Weight70 kg
Height1.75 m

BMI = 70 ÷ (1.75 × 1.75) = 22.86. Rounded to one decimal place, the displayed BMI is 22.9, within the standard healthy-weight reference range.

This example is illustrative. Change the assumptions to match your situation and review any page-specific notes before relying on the result.