How BMI is calculated
BMI divides weight in kilograms by height in metres squared. It is a simple screening measure used for adults.
BMI calculator
Calculate BMI and add context over time
Use the free calculator for a quick estimate, then follow weight and body measurements as part of a broader progress picture.
Calculate your BMI
BMI is a screening estimate, not a diagnosis. Age, muscle mass, pregnancy and medical conditions can affect interpretation.
Standard adult ranges
Below 18.5 is considered underweight, 18.5–24.9 healthy, 25–29.9 overweight and 30 or higher a high BMI range.
Look beyond one number
Training experience, muscle mass and health history matter. Follow trends and speak with a qualified professional when needed.
FAQ
Is BMI a medical diagnosis?
No. BMI is a screening estimate and cannot replace individual medical assessment.
Who should interpret BMI carefully?
Athletes, children, older adults, pregnant people and anyone with relevant medical conditions need additional context.