Absolute Error Calculator

This absolute error calculator works out how far a measured value sits from the true or accepted value, giving you a clean, positive number you can quote in a lab report, an engineering check or any piece of measurement work. You enter two figures: the measured value you recorded and the true (accepted) value you are comparing it against. From those two inputs the calculator returns the absolute error, calculated as the absolute value of the measured value minus the true value, so it is always shown as zero or positive and in the same units as your measurement. Alongside the headline result it also shows the relative error as a percentage, dividing the absolute error by the true value so you can judge how significant the gap is, plus the true value you entered for reference. A small absolute error can still be a large relative error if the true value itself is small, and this calculator shows both at once so you are not left guessing. Type in your own numbers, or use the worked example below (measured 9.8 against a true value of 10, giving an absolute error of 0.2 and a relative error of 2 percent) to see how the maths works before you rely on it. It is a quick check for coursework, experiments and quality control, not a substitute for a full uncertainty analysis.

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