Accuracy Basics

There are two metrics for measuring error: the absolute error and the relative error. Absolute error refers to the difference between the actual value and the measured value, and relative error refers to the ratio of the difference to the actual value. See the following equations:

• Absolute error = |Actual value – Measured value|
• Relative error = |Actual value – Measured value|/Actual value

Relative error is typically used to measure the operator accuracy, which is usually expressed as a percentage.