The Percent Error Calculator compares an experimental or measured value with an accepted or reference value and expresses the difference as a percentage. It is commonly used in laboratory work, science classes, experiments, and situations where a measured result needs to be compared with a known value.
Percent Error Formula
The standard formula is Percent Error = |Measured Value β Accepted Value| Γ· |Accepted Value| Γ 100. The absolute value makes the result a measure of the size of the error rather than its direction.
How to Use the Calculator
- Enter the measured or experimental value.
- Enter the accepted or reference value.
- Calculate the result.
- Read the percentage as the relative difference between the two values.
Worked Example
If a measured value is 9.8 and the accepted value is 10, the absolute difference is 0.2. Dividing 0.2 by 10 and multiplying by 100 gives a percent error of 2%.
Interpreting the Result
A smaller percentage generally means the measured result is closer to the accepted value. Percent error does not by itself explain why a difference occurred. Instrument limitations, experimental conditions, rounding, and measurement technique can all contribute to the result.