About the Percent Error Calculator
Calculate percent error between an experimental (measured) value and the true (accepted) value, as used in science labs.
Also known as: percentage error, experimental error, relative error, error percentage.
How to use this calculator
- Enter measured value, true value.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Open “Step-by-step” to see how the answer was worked out.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
% error = |Measured − True| ÷ |True| × 100
Worked example
Using the values pre-filled in the calculator above:
- Measured value = 9.6
- True value = 9.81
the calculator returns:
- Percent error: 2.1407%
- Absolute error: 0.21
- Relative error: 0.021407
Working
|9.6 − 9.81| ÷ |9.81| × 100 = 2.1407%