Free BMI Calculator — Body Mass Index Online
Calculate your Body Mass Index (BMI) and see your weight category — underweight, normal, overweight, or obese.
BMI Calculator
Frequently Asked Questions
What is a normal BMI for adults?
A BMI between 18.5 and 24.9 is considered normal weight. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese.
Is BMI accurate for everyone?
BMI is a screening tool, not a diagnostic measure. It may overestimate body fat in muscular people (like athletes) and underestimate it in older people who have lost muscle mass. Always consult a healthcare provider for a full assessment.
How do I calculate BMI?
BMI = weight in kg ÷ (height in meters)². For example, someone who weighs 70 kg and is 1.75 m tall has a BMI of 70 ÷ (1.75²) = 22.9.
What BMI is considered obese?
A BMI of 30 or higher is classified as obese. BMI 30–34.9 is Class 1 (moderate) obesity, 35–39.9 is Class 2 (severe), and 40+ is Class 3 (very severe).