Percent Error Calculator
Percent error between measured and true values, as used in science labs.
What is a percent error calculator?
A percent error calculator finds how far a measured value is from the true value, as a percentage. Example: experimental 98 against theoretical 100 gives 2% error.
How to use it
Enter the experimental value and the theoretical value, then tap Calculate.
Formula
Percent error = |experimental − theoretical| ÷ |theoretical| × 100. For 98 and 100: |98 − 100| ÷ 100 × 100 = 2%.
Example
Experimental 98, theoretical 100: |98 − 100| = 2, 2 ÷ 100 = 0.02, 0.02 × 100 = 2%. The measurement is 2% off the true value.
Frequently Asked Questions
What is the percent error of 98 against 100?
2%.
What does 0% error mean?
The measured value equals the true value exactly.
Can percent error be negative?
No, the absolute difference is used, so it is always 0% or more.
More calculators: Math Tools and All Tools.