Relative Error Calculator

What This Relative Error Calculator Does

This tool compares a measured value with an actual value and returns signed error, absolute error, relative error, and percent error. It updates in real time, which makes it useful for lab work, estimation checks, and rounding analysis.

Absolute And Relative Error Formulas

$$\text{absolute error} = |x_{\text{actual}} - x_{\text{measured}}|$$

$$\text{relative error} = \frac{|x_{\text{actual}} - x_{\text{measured}}|}{|x_{\text{actual}}|}$$

$$\text{percent error} = 100 \times \text{relative error}$$

Why Relative Error Is Useful

Absolute error keeps the original unit, but relative error shows the error as a fraction of the true value. That makes it easier to compare measurements across very different scales. For related uncertainty work, check our Percent Error Calculator and Error Propagation Calculator.