📐 Math Calculator

Percent Error Calculator

Calculate the percent error between an experimental (measured) value and the theoretical (accepted) value — used in science and engineering to assess measurement accuracy.

Your Values

Enter experimental and theoretical values
Formula: % Error = |Experimental − Theoretical| ÷ |Theoretical| × 100

Frequently Asked Questions

What is percent error?
Percent error measures how far an experimental result is from the accepted (true) value — expressed as a percentage. Formula: % Error = |E − T| ÷ |T| × 100. Lower is better.
Is 5% error acceptable?
In most high school science labs, less than 5% error is considered acceptable. In engineering or precise research, ≤1% or even less may be required. The acceptable threshold depends on the context.