How to Calculate Percent Error Calculator
What is Percent Error Calculator?
Percent error measures the accuracy of an experimental or measured value compared to an accepted or theoretical value. It expresses the discrepancy as a percentage, making it easy to compare errors across different scales and units.
Step-by-Step Guide
- 1Percent error = |Experimental − Theoretical| / |Theoretical| × 100%
- 2The absolute value removes the sign — percent error is always positive
- 3Signed percent error indicates direction: positive = measured too high, negative = too low
- 4Used in chemistry, physics, engineering, and manufacturing quality control
Worked Examples
Input
Measured density: 9.7 g/cm³, True density: 10.0 g/cm³
Result
3.0% error
|9.7−10| / 10 × 100 = 3%
Input
Predicted 50, actual 47
Result
6.0% error
|50−47| / 47 × 100 = 6.38%