Medication dosing typically utilizes three systems of measurement: the metric system, household system, and apothecary system. Drug calculations may be performed using a variety of methods, including dimensional analysis, formula method, or ratio proportion method.

Of the three systems of measurement, the metric system provides the most accurate dose calculations. Nurses play a critical role in ensuring safe medication administration.

ratio — comparison of one quantity to another, often described as a division problem. systems of measurement — collections of measurement units and how they are associated with one another. formula method — divides the desired amount by the amount on hand, then multiplies it by the quantity on hand to determine the dose. household system — utilizes everyday household items, such as measuring cups and tablespoons, to serve as the measuring device.