Common Systems of Weights and Measures

COMMON SYSTEMS OF WEIGHTS AND MEASURES
METRIC SYSTEM
Metric Weight     Metric Liquid Measure
1 femtogram (fg) = 0.001pg     1 femtoliter (fL) = 0.001pL
1 picogram (pg) = 0.001ng     1 picoliter (pL) = 0.001nL
1 nanogram (ng) = 0.001μg     1 nanoliter (nL) = 0.001μL
1 microgram (μg) = 0.001mg     1 microliter (μL) = 0.001mL
1 milligram (mg) = 0.001g     1 milliliter (mL) = 0.001L
1 centigram (cg) = 0.01g     1 centiliter (cL) = 0.01L (10 mL)
1 decigram (dg) = 0.1g     1 deciliter (dL) = 0.1L (100 mL)
1 gram (g) = 1g     1 liter (L) = 1L (1000 mL)
1 dekagram (dag) = 10g     1 dekaliter (daL) = 10L
1 hectogram (hg) = 100g     1 hectoliter (hL) = 100L
1 kilogram (kg) = 1000g     1 kiloliter (kL) = 1000L
APOTHECARY SYSTEM¹
Apothecary Weight Equivalents     Apothecary Volume Equivalents
1 grain² (gr) = 1 gr     1 minim () = 1
1 scruple () = 20 gr     1 fluidram (fʒ) = 60
1 dram (ʒ) = 60 gr = 3     1 fluid ounce (f) = 480  = 8 fʒ
1 ounce () = 480 gr = 8 ʒ     1 pint (pt or 0) = 7680  = 16 f
1 pound (lb) = 7680 gr = 16      1 quart (qt) = 15360  = 32 f
1 gallon (gal or cong) = 61440  = 128 f
AVOIRDUPOIS SYSTEM³
Avoirdupois equivalents
1 ounce (oz) = 437.5 grains
(gr)
1 pound (lb) = 16 ounces (oz) =
7000 grains (gr)

¹Apothecary—used in preparation of pharmaceuticals.

²The grain in each of the above systems has the same value and thus serves as a basis for the interconversion of the other units.

³Avoirdupois is used by manufacturers and wholesalers.

(Rev. 6/2020)