How to Take the Absolute Value of Percent Error

Absolute value is a simple notion that sounds complicated. Practically, absolute value just means stripping a number of a negative sign if the sign is already negative or leaving the number alone if positive. For example, -23 and 23 have the same absolute value, 23. This is useful is measuring degrees of difference without regard for whether a difference is negative or positive. To take the percent error in this way, it shows the degree of an error only. As such, even though the positive or negative quality of an error is significant, sometimes you just need to gauge the amount of the error.

Instructions

1. • 1

     Subtract the correct quantity from the erroneous quantity to determine the amount of the error. So if the erroneous figure is 134 and the correct figure is 157, the result is -23.

   • 2

     Determine the percent error, dividing the amount of the error by the correct quantity. Here, -23 divided by 157 gives a result of -0.146, or -14.6 percent.

   • 3

     Remove the negative sign from your percent error, if there is one. In this case, the absolute value of the percent error is 14.6 percent. Had your result been positive, for example 14.6 percent, you would not change the figure, and it would remain 14.6 percent.