Calculate the percent error between an experimental and true value.
Calculated locally in your browser.
Understanding your result
A smaller percent error means a more accurate measurement.
Formula and method
Percent error = |experimental − theoretical| ÷ |theoretical| × 100.
Worked example
An experimental value of 98 against a true value of 100 is a 2% error.
How to use this tool
- Enter the experimental value.
- Enter the true (theoretical) value.
Common mistakes to avoid
- Using zero as the theoretical value (undefined).
About the Percent Error Calculator
Measure how far an experimental result is from the true value as a percentage.
Frequently asked questions
Is percent error always positive?
The standard definition uses absolute values, so it is reported as a non-negative percentage.