Formula
Percent error uses the accepted value as the base:
Percent error = |measured − accepted| / |accepted|
The result is an absolute percent. It does not say whether the measurement was high or low.
Assumptions
- The accepted value is not zero.
- Both numbers use the same unit.
Worked example
A measured 98 against an accepted 100 has a percent error of 2.00%.
Input definitions
- Measured value
- The observed result.
- Accepted value
- The reference value used as the base.
Limitations
This is not a lab uncertainty or a grading curve.
Questions
Does a high measurement look different from a low one?
No. Both are the same percent error because the difference is absolute.
What if I do not have an accepted value?
Use percentage difference, which treats the two numbers equally.