**Error**

Error = Experimental Value - Known Value

**Relative Error**

Relative Error = Error / Known Value

**Percent Error**

% Error = Relative Error x 100%

**Example Error Calculations**

Let's say a researcher measures the mass of a sample to be 5.51 g. The actual mass of the sample is known to be 5.80 g. Calculate the error of the measurement.

Experimental Value = 5.51 g

Known Value = 5.80 g

Error = Experimental Value - Known Value

Error = 5.51 g - 5.80 g

Error = - 0.29 g

Relative Error = Error / Known Value

Relative Error = - 0.29 g / 5.80 g

Relative Error = - 0.050

% Error = Relative Error x 100%

% Error = - 0.050 x 100%

% Error = - 5.0%