Body Composition Score
Instructions
Enter your sex, age, height, weight, and body fat %. Height is to be entered in inches or cm. If you don't know your body fat %, you can estimate it using the linked calculator.
What is body composition?
Body composition is the percentages of fat, bone, organs, water, and muscle in the body and is a good marker of overall health and fitness. It is highly correlated with health outcomes and physical appearance. Some of the most common fitness goals, like losing fat, involve improving it. As such, knowing and tracking body composition can be incredibly helpful.
The two factors that determine your body composition are body fat percentage (BFP) and adjusted fat free mass index (AFFMI). BFP is the total percentage of fat in the body and AFFMI is the amount of fat free mass relative to height. Although AFFMI does include bone and water mass, these are accounted for in the ranking ranges and any changes can be minimized by taking your measurements under similar conditions each time. This allows for AFFMI to be an accurate metric for overall muscle mass.
Body Fat %
Body fat percentage (BFP) is the percentage of body mass that is attributed to fat tissue. It has significant effect on health risks, physical performance, and physical appearance. It is a great metric for measuring progress as losing weight, specifically fat, is a common health goal. However, for your BFP to be considered healthy, it can't be too low or too high.
What is considered a healthy BFP depends largely on sex and age. The healthy range for women is higher than men as women naturally carry more fat tissue. For example, the healthy range for a young man is from 8% to 20% BFP while for a young woman, the healthy range is from 20% to 33%. Also, as you age, the healthy range increases. This is due to more fat being stored as subcutaneous fat rather than as visceral fat.
Adjusted Fat Free Mass Index
Your adjusted fat free mass index (AFFMI) is your fat free mass normalized for height and is representative of overall muscularity. This makes it a great metric for measuring progress since gaining muscle is a common fitness goal. It is also an indicator of overall health. Up to a point, a higher AFFMI is associated with better health outcomes and there are many benefits to having more muscle.
AFFMI is similar to BMI, but is a much more accurate metric of health and fitness, especially in combination with BFP. Simply using BMI, a lean athlete may appear the same as an average person of the same height and weight even though they're in much better shape. However, using AFFMI and BFP, the athlete would be shown to have more muscle mass and less fat.
What does my rank mean?
Your body composition rank is based on your body fat %, adjusted fat free mass index, and where they place on your sex and age adjusted scales. The ranks are meant to represent how the body compositions that fall within them affect health, physical performance, and physical appearance. That being said, there are a variety of different body compositions that fall within each rank. This is intended, as different physical pursuits are suited to different body compositions. However, health and balance is prioritized. Meaning that, although having a higher body fat % can increase strength, it is not necessarily healthy and will lead to a lower rank.
The Fitness Score System
Body composition is just one of the components of physical fitness. For more score calculators like this, check out the resources page to find your strength score, cardio score, and more. As part of our highly customizable workout tracking and health data tracking, these scores are automatically calculated and can be seen on your fitness dashboard.
