Error = Measured value – True value
Absolute error = |Measured value – True value|
Relative error = Absolute error / True value
Percentage error = (Absolute error / True value) × 100%
If comparing two measurements, error = Difference between the values
If using a predicted value, error = Actual value – Predicted value
For repeated measurements, error can be estimated using the mean of the measurements
For uncertainty, error is often reported as ± value