Body Mass Index (BMI)

Also known as: BMI Formula, Body Mass Index Calculation

BMI = \frac{\text{weight (kg)}}{\text{height (m)}^2}

BMI = weight(kg) / height(m)²

What It Calculates

A screening tool that uses height and weight to estimate body fat. Categories: Underweight (<18.5), Normal (18.5–24.9), Overweight (25–29.9), Obese (30+). BMI does not measure body fat directly and may not be accurate for athletes or elderly.

variables

Symbol	Name	Unit	Description
BMI	Body Mass Index	kg/m²	A screening measure for weight categories
weight	Weight	kg	Body weight in kilograms
height	Height	m	Height in meters

Worked Examples

1BMI = 70 / 1.75²

2BMI = 70 / 3.0625 = 22.86

Result: 22.86 (Normal)

Common Mistakes

BMI doesn't distinguish between muscle and fat

Use imperial formula if using lbs/inches: (weight × 703) / height²

Try a Calculator

bmi ideal body weight

Related Formulas

Basal Metabolic Rate (Mifflin-St Jeor)

BMR = 10×weight(kg) + 6.25×height(cm) - 5×age + s

Body Fat Percentage (Navy Method)

BF% = 86.010×log10(waist-neck) - 70.041×log10(height) + 36.76

#body composition#screening#weight