Everyday Math

Math, Numbers, and the Body

Why is measuring medications so difficult?

There are many ways that medications are measured, which often leads to confusion when someone asks what kind, amount, and dosage of medications you consume (and why doctors recommend you to carry a list of your medications, along with the amount of each pill and dosage).


How much is a “teaspoon” of medicine? Because people often measure medicines in different ways at home, it is common that people do not administer correct dosages for themselves or their children.

Pills come in a wide variety of types, of course, ranging from tiny and round to what was once referred to as very large “horse pills.” Most pills have the needed ingredient—usually 5 to 10 percent of the tablet—along with other substances that either make them palatable or easier to swallow, and allow the pill to dissolve in your system. Dosage is the most confusing topic when taking a medication. Many times, a label will read, “one teaspoon before bedtime.” But the problem comes in when you realize that not everyone has the same teaspoon, or measures the same way. In fact, in one study, people were asked to pick out a spoon size that would measure 5 milliliters, the proper measurement meant by “a teaspoon” when using medications. Most people chose spoons (they ranged from 4.4 to 10 milliliters) that were higher in dosage, sometimes choosing a spoon that would give them double the dose. This is why doctors recommend a medicine spoon or dosing syringe.

The following is a list of numbers that you may see in your medicine cabinet. Many medicines (seen with pills mostly) are measured using metric weights:

  • 1 kilogram (kg, Kg) = 1,000 grams (1000 g)
  • 1 gram = 1,000 milligrams (1000 mg)
  • 1 milligram = 1,000 micrograms (1000 mcg)
  • 1 microgram = 0.001 milligrams (0.001 mg)
  • 1 milligram = 0.001 gram (0.001 g)
  • 1 microgram = 0.000001 gram (0.000001 g)

And in terms of measuring out dosages, the following lists some of the more common measurements:

  • 1 cubic centimeter (cc) = 1 milliliter (ml)
  • 1 teaspoon = 5 cc = 5 ml
  • 1 tablespoon = 15 cc = 15 ml = 3 teaspoons
  • 1 ounce (oz) = 30 cc = 30 ml = 2 tablespoons = 6 teaspoons


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