Percent Error

In an experiment, it is important to be able to describe how close you came to the accepted or “correct” result.  This is done by describing the percent error.

percent error: how far off your result was as a percentage of the accepted or “correct” value.

The formula for percent error is:

% error =

The vertical bars mean “absolute value,” which means if you get a negative number, change the sign to make it positive.

For example, if the correct value were 100 and you got 95, your percent error would be:

      % error =  = 5%