Free Math Tool
Percentage Error Calculator
Calculate the percentage error between experimental and theoretical values.
Percentage Error
0%
Percentage Error Calculator
Our percentage error calculator measures how far an experimental value is from the true/theoretical value.
% Error = |Experimental − Theoretical| / |Theoretical| × 100
Example: Measured 9.8, True 10: Error = |9.8-10|/10 × 100 = 2%
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Frequently Asked Questions
What is percentage error?
Percentage error = |Experimental - Theoretical| / |Theoretical| × 100. It measures how far a measurement is from the true value.
What is a good percentage error?
It depends on context. For precise lab work: <1% is excellent, <5% is good. For rough estimates: <10% may be acceptable.
Can percentage error be negative?
The absolute value is typically used (positive). However, you can report signed error to show direction: positive if experimental > theoretical.