Compare an experimental value against the accepted true value to get the percent error of a measurement or estimate.
Enter the measured and the accepted true value.
Enter numbers to see the result.
Percent error divides the signed gap between your measurement and the accepted value by the accepted value. A result of +3% means the measurement read high; -3% means it read low. The absolute percent error drops the sign when you only care about magnitude.
Percent error needs a known true value to measure against, which is why it is a lab staple. Percentage difference is used instead when you are comparing two measurements with no accepted reference, because it measures against their average.