How does the InBody body composition analyzer calculate the fitness score?

Regarding the fitness score:

The InBody Score is an arbitrary score based on the measured muscle and fat mass for the motivation of the subjects (ref).

Here is a sample result sheet from the maker's web site. See the bottom right corner for the fitness score:

results sheet


You'll have to ask them, as it's calculated using their own proprietary algorithm, well that or spend a few min's solving the simultaneous equation (from the values in your history) to work out the weights they've applied to your: Fat, Muscle, and Weight values to create the score:

The fitness score is to help the subject to understand his/her body condition from a body composition point of view. The ideal is 100%. It is a piece of unique data provided by InBody720


*Fitness Score

The Fitness Score is an index used to help the examinee easily understand the state of his/her body composition.

70 or less weak or obese type that need exercise and diet control

70~90 Normal, Healthy Type

90 or more Robust type with well-developed muscle

FYI: Using R to play with the DUMMY values above

weight <- c(65.7, 63.5, 61.2, 59.1)
smm <- c(20.6, 19.4, 19.4, 19.6)
fat <- c(27.0, 25.8, 23.5, 21.8)
score <- c(62, 63, 66, 68)
test.data = data.frame(score, weight, smm, fat)
lm(score ~ ., data = test.data)


lm(formula = score ~ ., data = test.data)

(Intercept)       weight          smm          fat  
   75.67391      0.54987      0.01279     -1.85422  

So for the DUMMY history above:

score = (0.54987 * weight) + (0.01279 * SMM) - (1.85422 * fat) + 75.67391

which if the same ratios hold in a real analysis, would suggest to exceed 100, you would need to have a dangerously low bodyFat %.

  • Wonderful analysis. I very much appreciate it! It looks in the ballpark. With my own numbers and the dummy formula above I would just exceed 103 points when on paper I'm at 97 points. It's interesting that SMM has negligible effect on the score though.
    – Drakes
    Jul 26 '15 at 13:35
  • @Drakes - you can just alter the numbers and run the code eg. r-fiddle.org/#/fiddle?id=lCB8ebYm
    – arober11
    Jul 26 '15 at 20:42

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