Relative Error Definition

What Is Relative Error?

Relative error is a measure of the uncertainty of a measurement compared to the entire measurement's magnitude.
Relative error is a measure of the uncertainty of a measurement compared to the entire measurement's magnitude. Caiaimage/Martin Barraud / Getty Images

Relative Error Definition: Relative error is a measure of the uncertainty of measurement compared to the size of the measurement. It's used to put error into perspective. For example, an error of 1 cm would be a lot if the total length is 15 cm, but insignificant if the length was 5 km.

Also Known As: relative uncertainty

Examples: Three weights are measured at 5.05 g, 5.00 g, and 4.95 g. The absolute error is ± 0.05 g.



The relative error is 0.05 g/5.00 g = 0.01 or 1%.