What is a healthy BMI?

A BMI between 18.5 and 24.9 is considered healthy for most adults. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is obese.

How is BMI calculated?

BMI = weight (kg) ÷ height² (m²). In imperial: BMI = 703 × weight (lbs) ÷ height² (inches²).

BMI is a screening tool, not a diagnostic measure. It may not be accurate for athletes, the elderly, pregnant women, or certain ethnic groups.

Calculate your Body Mass Index in metric or imperial units.

Height (cm)

Weight (kg)

Underweight < 18.5

Normal 18.5 – 24.9

Overweight 25 – 29.9

Obese ≥ 30

BMI is a screening tool, not a diagnosis. Consult a healthcare professional for medical advice.

How is BMI calculated?: BMI = weight (kg) ÷ height² (m²). For imperial: BMI = 703 × weight (lbs) ÷ height² (inches²).
Is BMI accurate for athletes?: Not always. Muscle weighs more than fat, so athletes may have a high BMI while being very healthy. BMI is a population-level screening tool.
What is the ideal BMI?: 18.5–24.9 is the "Normal weight" range defined by the WHO for adults.