Percent Difference: Applied when comparing two experimental quantities, Exp1 and Exp2, neither of which can be considered the “correct” value. The percent difference is the absolute value of the difference over the mean times 100.
mean = (E1 + E2)/2
% Difference = |E1 − E2| / mean
Where as the Percent Error: Percent Error: Applied when comparing an experimental quantity, Exp, with a theoretical quantity, T, which is considered the “correct” value. The percent error is the absolute value of the difference divided by the “correct” value times 100.
% Error = |T − Exp|*100 / T