Enter the measured value and actual value into the calculator below to determine the relative error (%) and the absolute error.

## Relative Error Formula

RE = (AV – MV) / AV *100

- Where RE is the relative error (%)
- AV is the actual value
- MV is the measured value

## Relative Error Definition

As is the case with the standard error, relative error is a measure of how close a measured value is to the true theoretical value. In the case of chemistry, this could be the measure mass to actual mass of a reaction.

This calculator also determines the absolute error, which is simply the absolute value of the actual value minus the measured value. This is an “absolute” value because it will always be positive.

## How to calculate relative error?

How to calculate relative error

**First, measure the actual value.**Measure the actual value, also known as the theoretical value, that the experiment should yield.

**Next, determine the measured value.**Measure the value that your experiment yielded.

**Finally, calculate your relative error.**Calculate the relative error using the formula above.

## FAQ

**What is a relative error?**

Relative error is a measure the the difference between an expected or theoretical outcome and the actual outcome that occurred.