Relative Uncertainty

The Relative Uncertainty calculator compute the relative uncertainty based on the absolute uncertainty and the magnitude of measurement.

INSTRUCTION: Enter the following:

• (AU) This is absolute uncertainty which is uncertainty associated with the reading of the instrument.
• (MM) This is the magnitude of measurement, which is the full measurement recorded in any units of volume or mass.

Relative Uncertainty (RU):  The calculator returns the uncertainty as a real number.  However this can be automatically converted to percentage via the pull-down menu.

Related Calculators

• Uncertainty in Multiplication and Division
• Uncertainty in Addition and Subtraction
• Relative Uncertainty

The Math / Science

The relative uncertainty^[1] equation calculates the ratio of the absolute uncertainty to the true value of the measurand. The equation for relative uncertainty is:

            RU =  AU / MM

where:

• AU is absolute uncertainty which is uncertainty associated with the reading of the instrument.
• MM is the magnitude of measurement, which is the full measurement recorded in any units of volume or mass.
• RU is relative uncertainty 

Related Topics

• Uncertainty in addition and subtraction (for the Spanish site click here)

References

Harris, D., Quantitative Chemical Analysis, 9th Ed., W. H. Freeman,  Pp.52 (2015).

[1] For the Spanish site click here.