Is BMI accurate for everyone?

BMI is a useful population-level screening tool but can be less reliable for athletes, older adults, growing children, and pregnant women because it cannot distinguish muscle from fat.

How is BMI calculated?

BMI is weight in kilograms divided by height in meters squared. This calculator converts pounds, feet, and inches automatically.

Is my data stored anywhere?

No. All calculations happen instantly in the browser and nothing entered is stored or shared.

⚖️ BMI Calculator

Check your Body Mass Index instantly using the standard WHO formula.

Height (cm)

Weight (kg)

Your BMI

— kg/m²

—

1518.5253040

Underweight Normal Overweight Obese

How BMI Is Calculated

Body Mass Index divides your weight in kilograms by the square of your height in meters. It's a quick screening number, not a full diagnosis — it doesn't account for muscle mass, bone density, or where fat is distributed in the body.

This calculator converts pounds, feet, and inches automatically if you switch to imperial units, so the formula always runs in metric behind the scenes.

Who Uses This Tool?

Anyone tracking their weight trend against a standard reference range
People starting a fitness or nutrition plan who want a baseline number
Patients preparing questions for a doctor or dietitian visit
Trainers and coaches doing a quick initial client screening

For most adults, the WHO classifies 18.5 to 24.9 as the normal range. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above falls into the obese category.

BMI is a useful population-level screening tool, but it can be less reliable for athletes with high muscle mass, older adults, growing children, and pregnant women, since it can't distinguish muscle from fat.

The formula divides weight in kilograms by height in meters squared. This calculator handles the pound/feet/inch conversion automatically.

No. All calculations happen instantly in your browser — nothing you enter is stored or shared.