BMI Calculator
Calculate your Body Mass Index (BMI) using our free BMI calculator. Enter your height and weight in metric or imperial units to instantly see your BMI score and weight category. The BMI calculator works for adults aged 20 and older.
BMI Calculator
health calculator
How It Works
BMI is calculated by dividing your weight in kilograms by the square of your height in meters. The WHO classifies BMI into four categories: Underweight (<18.5), Normal (18.5-24.9), Overweight (25-29.9), and Obese (≥30).
Formula
BMI = weight (kg) / height² (m) BMI (Imperial) = 703 × weight (lbs) / height² (inches)
Examples
70kg, 175cm adult
Average adult male in the normal BMI range.
Frequently Asked Questions
What is a healthy BMI?
According to the WHO, a healthy BMI range is 18.5 to 24.9. Below 18.5 is underweight, 25-29.9 is overweight, and 30 or above is obese.
Is BMI accurate?
BMI is a useful screening tool but not a perfect measure of health. It doesn't account for muscle mass, bone density, age, or ethnic differences. Athletes may have high BMI due to muscle, not fat.
What is the BMI for children?
For children aged 2-19, BMI is calculated the same way but interpreted differently using age- and sex-specific percentiles, not the adult thresholds.
How can I lower my BMI?
BMI can be lowered through a combination of healthy diet and regular exercise. Even a 5-10% reduction in body weight can significantly improve health outcomes.
Related Calculators
Calorie Calculator
Free calorie calculator. Find your daily calorie needs to maintain, lose, or gai...
PopularBody Fat Calculator
Free body fat percentage calculator using the US Navy method. Estimate your body...
Ideal Weight Calculator
Free ideal weight calculator. Find your ideal body weight based on height and ge...
BMR Calculator
Free BMR calculator. Find your Basal Metabolic Rate — the calories your body bur...