What is BMI and how is it calculated?

BMI (Body Mass Index) is a screening tool that measures body fat based on height and weight. It's calculated by dividing weight in kilograms by height in meters squared (kg/m²). In imperial units it is 703 times weight in pounds divided by height in inches squared.

What are the BMI categories?

BMI categories include: Underweight (below 18.5), Normal weight (18.5-24.9), Overweight (25-29.9), and Obese (30 and above). These are general guidelines for adults.

Is BMI a complete measure of health?

No, BMI is a screening tool but doesn't directly measure body fat or health. Factors like muscle mass, bone density, and age can affect interpretation. Always consult healthcare professionals for comprehensive health assessment.

Does the calculator store my calculation history?

Yes, the BMI calculator includes a calculation history feature so you can track your BMI over time and monitor changes.

Free Online BMI Calculator (No Signup)

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Healthy Weight Range (for your height)

BMI Prime

Ideal Weight (Devine)

Waist-to-Height Ratio

Body Fat % (estimate)

Basal Metabolic Rate

BMI Categories (adults):

Underweight: BMI below 18.5
Normal weight: BMI 18.5 to 24.9
Overweight: BMI 25 to 29.9
Obesity: BMI 30 or higher

Note: BMI is an informational screening tool and does not directly measure body fat or overall health. Muscle mass, bone density, age, sex and ethnicity can all affect interpretation. This tool is not medical advice — always consult a qualified healthcare professional for a complete health assessment.

BMI Calculator

BMI History