Free BRI Calculator

What is the Body Roundness Index?

The Body Roundness Index (BRI) is a relatively new measure developed to improve upon the limitations of the Body Mass Index (BMI). Unlike BMI, which calculates body fat based on height and weight, BRI uses waist circumference and height, offering a clearer picture of abdominal fat distribution. This focus is more helpful, as abdominal or visceral fat—the fat stored around internal organs—plays a significant role in the risk of developing chronic health conditions such as heart disease, Type 2 diabetes, and certain cancers.

About our BRI calculator

Our Body Roundness Index calculator helps you quickly determine your BRI based on waist circumference and height. It supports both inches and centimeters.

Best of all, it’s completely free, online, anonymous, and requires no login. The calculator works directly in your browser without sending any of your private health data to a server, ensuring your privacy and security.

While our BRI calculator provides a quick and easy way to assess your body shape, it is not a substitute for professional medical advice. Please consult a healthcare professional for a comprehensive evaluation of your health.

Why Is BRI More Accurate Than BMI?

While BMI has been widely used for decades, it has limitations. BMI doesn’t distinguish between fat and muscle, often misclassifying muscular individuals (like athletes) as "overweight" or "obese," even though they have low body fat and are perfectly healthy. Additionally, BMI overlooks variations in body shape, such as ethnicity, age, gender and fat distribution. Older adults, for instance, may appear healthy based on BMI but could be at risk due to loss of muscle and an increase in fat, especially around the waist.

In contrast, BRI offers a more nuanced estimate of central obesity, the accumulation of fat in the abdomen, which is strongly correlated with metabolic and cardiovascular diseases. Studies, such as those published in JAMA Network Open, have demonstrated that BRI is a superior predictor of health risks when compared to BMI, particularly regarding conditions related to central obesity. As such, BRI is increasingly recognized as a more reliable tool for assessing body shape and associated health risks.

How is BRI Calculated?

To calculate BRI, two primary measurements are required: waist circumference and height. Unlike BMI, weight is not factored into the equation. The BRI formula generates a score ranging from 1 to 20, where higher scores correspond to a rounder body shape, with greater amounts of abdominal fat. A lower BRI score suggests a leaner body with less abdominal fat, whereas scores closer to 20 indicate a higher accumulation of fat around the waist, which increases the risk for health problems like heart disease and diabetes.

We use the following formula developed by Thomas et al. to calculate the BRI:

Health Implications of Your BRI Score

• Low BRI (Smaller than 3.4): Indicates minimal abdominal fat, representing a healthier body composition. However, extremely low scores might signal risks tied to being underweight.
• BRI between 3.4 and 5.5: Suggests a balanced body shape, often reflecting the healthiest range for most individuals.
• BRI between 5.5 and 6.9: Your BRI is slightly above the optimal range. While the risk is not as high as in extreme cases, it’s recommended to adopt healthier habits to reduce potential risks.
• High BRI (Larger than 6.9): Reflects a higher concentration of visceral fat in the abdominal region. This is linked to an elevated risk of serious conditions such as cardiovascular disease, Type 2 diabetes, and other obesity-related illnesses. Research shows a 49% increased risk of all-cause mortality for those with a BRI of 6.9 or greater. It is recommended to consult a healthcare professional for personalized advice.