BMI calculator

Calculate Body Mass Index from weight in kilograms and height in centimeters, with the standard category.

Weight (kg) Height (cm)

BMI: -

Enter weight and height.

Formula and algorithm

BMI = weight (kg) ÷ height (m)²
Categories: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obesity.
BMI is a general screening tool, not a diagnosis or medical advice.

Input: 70 kg, 175 cm

Output: BMI 22.9 (Normal)

70 ÷ 1.75² = 22.86, within the normal range.

Input: 85 kg, 175 cm

Output: BMI 27.8 (Overweight)

85 ÷ 1.75² = 27.76.

Input: 50 kg, 175 cm

Output: BMI 16.3 (Underweight)

50 ÷ 1.75² = 16.33.

Is BMI accurate for everyone?

No. It does not distinguish muscle from fat, so athletes and some body types can be misclassified. It is a screening tool only.

Is this medical advice?

No. RapidUnits does not provide medical advice; consult a healthcare professional for health decisions.

What units does it use?

Weight in kilograms and height in centimeters.

Updated: June 7, 2026