BMI Calculator (Body Mass Index)
Calculate your Body Mass Index (BMI) and find your healthy weight range. Free BMI calculator for adults using height and weight.
How This Calculator Works
Calculation methodology and assumptions
BMI = (Weight in pounds ÷ Height in inches²) × 703. Categories: Underweight (<18.5), Normal (18.5-24.9), Overweight (25-29.9), Obese Class I (30-34.9), Obese Class II (35-39.9), Obese Class III (40+). BMI is a screening tool, not a diagnostic measure — it doesn't distinguish between muscle and fat mass.
Frequently Asked Questions
What is a healthy BMI?
A BMI between 18.5 and 24.9 is considered normal/healthy weight. However, BMI doesn't account for muscle mass, bone density, or body composition. Athletes may have a "high" BMI but low body fat.
How accurate is BMI?
BMI is a useful screening tool for populations but has limitations for individuals. It overestimates body fat in muscular people and underestimates it in older adults with muscle loss. Consider using it alongside waist circumference and body fat percentage.