Pharmacy Math Conversions

What are the three systems of measurements?

Metric

Apothecary

Avoirdupois

1 gram

1,000 milligrams (mg)
1,000,000 micrograms (mcg)

1 kilogram (kg)

1,000 grams

1 liter (L)

1,000 milliliter (mL)

1 kilometer (km)

1,000 meters (m)

kilo

1,000 units

hecto

100 units

deka

10 units

deci

0.1 unit

centi

0.01 unit

milli

0.001 unit

1 grain (gr)

60 mg

1 grain (gr) - acetaminophen, ferrous sulfate, acetylsalicylic acid

65 mg

1 fl dr

5 mL

a dram

1 tsp

¼ dram

15 minims

½ drams

30 minims

¾ drams

45 minims

1 dram

60 minims

1 lb

16 oz

1 tbsp

3 tsp

15 mL

1 fl oz

30 mL