BMI Calculator
Calculate your Body Mass Index (BMI) to find out if you are in a healthy weight range. Supports both metric and imperial units.
How to Use This BMI Calculator
Our free BMI calculator helps you quickly determine your Body Mass Index, a widely used measure to assess whether your weight falls within a healthy range for your height. All calculations are performed entirely in your browser -- no data is sent to any server.
Step-by-Step Instructions
- Choose your unit system -- select Metric (kg/cm) or Imperial (lbs/ft+in).
- Enter your height -- in centimeters for metric, or feet and inches for imperial.
- Enter your weight -- in kilograms for metric, or pounds for imperial.
- Click "Calculate BMI" to see your BMI value, category, a visual scale, and your healthy weight range.
BMI Formula
BMI is calculated as weight in kilograms divided by the square of height in meters: BMI = weight (kg) / height (m)². For imperial units, the calculator first converts your height to meters and weight to kilograms before applying the formula.
Frequently Asked Questions
What is BMI?
Body Mass Index (BMI) is a numerical value derived from your weight and height. It provides a simple, widely used screening tool to categorize individuals as underweight, normal weight, overweight, or obese.
Is BMI an accurate measure of health?
BMI is a useful screening tool but has limitations. It does not distinguish between muscle and fat mass, so athletes with high muscle mass may have a high BMI despite being healthy. It also does not account for age, sex, bone density, or fat distribution. Always consult a healthcare professional for a comprehensive health assessment.
What is a healthy BMI range?
A BMI between 18.5 and 24.9 is generally considered "normal weight" for adults. Below 18.5 is classified as underweight, 25.0 to 29.9 is overweight, and 30.0 or above is obese. These categories apply to adults aged 20 and older.
Does BMI apply to children and teenagers?
For children and teens (ages 2-19), BMI is interpreted differently using age- and sex-specific percentiles rather than fixed categories. This calculator is designed for adults. Consult a pediatrician for children's BMI assessment.
How can I reach a healthy BMI?
Reaching a healthy BMI typically involves a combination of balanced nutrition and regular physical activity. Small, sustainable changes in diet and exercise habits are more effective than extreme measures. Consult a healthcare provider before starting any weight management program.