Nursing involves doing math calculations commonly used in the field. Nurses use math calculations to regulate fluids, convert measurement, and calculate drug dosages. While programs, pumps and calculators actually do the math, nurses must be able to calculate without using them. These items may not always be available, such as in a natural disaster when there is no electricity. Most importantly, nurses must be able to do calculations without errors to ensure the safety of patients. Concentrating on a few essential math skills allows nurses to be proficient.

Metric System Conversions

Conversions are essential and the nurse should know how to do them, particularly those involving the metric system. Metric is the measurement system used in medical settings. Nurses need to be able to convert from one system of measurement to another, such as from the metric system to the English system and vice versa.

Basic Mathematics

All of nursing math consists of a few basic skills. Nurses must be able to add, subtract, multiply and divide decimals, fractions and whole numbers. Other important basic math skills for nurses include converting decimals to percentages, percents to decimals, doing fractions as well as knowing how to solve ratio and proportion problems. Decimal placement is very important in drug dosage calculations. Wrong placement could result in an overdose 10 times the normal dosage. Understanding Roman numerals and knowing how to convert them to regular numbers is also essential.

Drug Dosage Calculations

Nurses need to do dosage calculations when a drug is in tablets, but the order is in milligrams (mg). A drug could also be only available in a certain amount, but ordered in a different one. An example would be if the order calls for 80 milligrams, but it’s available in tablets of 20 milligrams each. The nurse must be able to calculate the right amount to give to the patient – in this case, four tablets. Sometimes nurses must calculate drug dosages according to body weight when administering medication to children. This type of order may call for 20 mg per kilogram (kg) of body weight, but is only available as four grams per milliliter (ml). The nurse would need to weigh the patient before calculating the dosage.

IV Flow

Nurses should know how to calculate an intravenous flow rate (IV) manually without the use of a pump. They do calculations to control the amount of fluid or medication given to a patient. Registered nurses (RNs) calculate IVs and IV medications; however, IV certified practical nurses (LPNs) or licensed vocational nurses (LVNs) can also do them. Calculations use a common formula: flow rate = volume/time. Nurses also use IV flow rate calculations to determine the time administration will finish. Nurses also should be familiar with different administration sets and tubing because it affects the amount of fluid or drug given.