Percent Error Calculator

Use this percent error calculator to compare a measured, observed or estimated value with an accepted, true or reference value. In one step, the tool returns percent error, relative error, absolute error and the simple difference between both numbers.

It works well for school exercises, lab reports, physics, chemistry, basic statistics, quality checks and quick answer reviews. It also helps separate two ideas that are often mixed up: percent error and percent difference. Here the denominator is the accepted value, not the average of both values.

Choose absolute mode for the standard classroom or lab interpretation. Choose signed mode when you want to keep the positive or negative direction of the deviation. The accepted value cannot be zero for this formula.