Nutrition Labels Are Inaccurate. And that Doesn't Matter. With a standard deviation of 150 calories, some errors exceeded 120% (i.e. a food labeled as 500 calories had 1,000+ calories or negative calories), most absolute errors were below 90%, and the average absolute error was 23-26% (i.e. the average error exceeded the maximum legal error). Obviously, the mean error for every test collapsed toward 0.