# Relative Error

## Definition - What does Relative Error mean?

A Relative Error is an experimental error in approximation or experimental testing and analysis methods. In order to understand and find relative error, absolute error needs to be determined first, because both these errors are interdependent on each other. In simple terms relative error is absolute error divided by the magnitude of the true value.

## Petropedia explains Relative Error

There are two types of errors in experimental testing and analysis methods, i.e., absolute error and relative error. The formula below gives the relationship between both the types of errors and also defines the relative error.

Here, the true value of the quantity is considered as “x” and the inferred value or the measured value of the quantity is considered as “x0”. This measured value is the value that is obtained from conducting an experiment whereas the true value is that value which is an ideal value as per the standard specifications.

In the above formula, Delta x is absolute error and is the difference between the measured value (inferred value) of the quantity and the true value of the quantity.