__NOTOC__ Also see the article :  Greek drachma.

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The dram (American spelling) or drachm (British spelling) was historically both a coin and a weight.

Currently drachm or dram is both

• a small mass in the system of weights avoirdupois and
• a small unit of volume. This unit is called more correctly fluid dram or in contraction also fluidram.

Drachm (mass)

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Ancient masses

• The Roman drachm was a weight of 1/96 Roman pounds, which is about 3.41 grams.
• The Greek drachm was a weight of 1/100 Greek mine, which is about 4.37 grams.

Greek and Roman drachm were related by the ratio 25 : 32.

Anglo-saxon masses

The dram is the mass of 1/256 pound avoirdupois and 1/16 ounce. So the dram weights 875 / 32 grains.

• 7  x  64.80000 / 256  =  1.771 875 000 000 0 gram :  This is the conventional, however not the official value of the mass called dram.
• 7  x  64.79891 / 256  =  1.771 845 195 312 5 gram :  This is the legal value, exactly one 99.9983179012345679 % of the value above.

Drachm (volume)

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The fluid dram is defined as 1/8 of a fluid ounce, which means it is exactly equal to

• 3.696 691 195 312 5 mL in the U.S. and
• 3.551 632 812 500 0 mL in most other Anglo-Saxon countries.

Dram is also used informally to mean a small amount of liquid, especially Scotch whisky.

See also

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• Avoirdupois
• Imperial unit
• U.S. customary units

Units of mass | Units of volume | Imperial units | Customary units in the United States

Dram (Einheit) | Dracma (unidad de masa) | Drachme (unité) | ドラム (単位)