BMI Calculator
Calculate your Body Mass Index (BMI) to understand your weight relative to your height. BMI is a screening tool based on WHO guidelines, not a diagnostic measure.
Frequently Asked Questions
What is BMI and how is it calculated?
Body Mass Index (BMI) is a numerical value calculated from your weight and height. The formula is weight in kilograms divided by height in meters squared (kg/m2). For imperial measurements, it is weight in pounds divided by height in inches squared, multiplied by 703. BMI is used by the World Health Organization (WHO) and healthcare providers worldwide as a screening tool to categorize weight status (Source: WHO Global Database on Body Mass Index).
Is BMI an accurate measure of health?
BMI is a useful screening tool but has important limitations. It does not directly measure body fat percentage, muscle mass, bone density, or fat distribution. Athletes with high muscle mass may have a high BMI despite having low body fat. Older adults may have a normal BMI but carry excess body fat. Additionally, BMI thresholds may not be equally applicable across different ethnic groups. For a more complete picture, healthcare providers often combine BMI with waist circumference, body composition tests, blood pressure, cholesterol levels, and blood sugar measurements (Source: CDC.gov, National Heart, Lung, and Blood Institute).
What should I do if my BMI is outside the normal range?
If your BMI falls outside the normal range (18.5-24.9), consider scheduling an appointment with your healthcare provider for a comprehensive assessment. They can evaluate your individual health factors including family history, lifestyle, diet, exercise habits, and any existing health conditions. Together, you can create a personalized plan that may include dietary modifications, physical activity recommendations, and if needed, further medical evaluation (Source: American Medical Association Guidelines on Obesity Assessment).
Does BMI apply to children and teenagers?
This calculator is designed for adults ages 20 and older. For children and teens (ages 2-19), BMI is calculated the same way but is interpreted using age- and sex-specific percentiles rather than fixed thresholds, because body composition varies significantly with age and developmental stage. A pediatrician can calculate and interpret BMI-for-age percentiles for children (Source: CDC Growth Charts, American Academy of Pediatrics).