How many grains are in one dram?

One avoirdupois dram contains exactly 27.34375 grains. This comes from the avoirdupois system: 7,000 grains per pound, 256 drams per pound, so 7,000 / 256 = 27.34375.

Why is the grains-per-dram number not a whole number?

Because the grain and dram were standardized independently within the avoirdupois system. The grain was set at 1/7,000 of a pound, and the dram at 1/256 of a pound. Their ratio (7,000 / 256) does not produce a whole number, reflecting the system's organic evolution rather than deliberate mathematical design.

Are both units still in use?

The grain remains actively used in ammunition manufacturing and some pharmaceutical contexts. The dram is largely obsolete, surviving only in a few specialized references. The grain has outlived the dram because it serves indispensable niches.

Drams to Grains (dr to gr) Converter

1 dr = 27.3438 gr

1 Dram equals 27.3438 Grains (1 dr = 27.3438 gr). Convert Drams to Grains with formula, table, and examples.

One dram equals exactly 27.34375 grains. Both units belong to the avoirdupois system, making this a purely internal imperial conversion. The dram (1/16 ounce) and the grain (1/7000 pound) share the same system but serve different applications: the dram for small trade goods and the grain for ammunition, pharmacy, and the finest increments of the avoirdupois scale.

How to Convert Drams to Grains

gr = dr × 27.34375

Multiply the value in Drams by 27.34375

Take your value in Drams
Multiply by 27.34375
Read the result in Grains

Common Drams to Grains Conversions

Drams (dr)	Grains (gr)	Status
0.25 dr	6.8359 gr
0.5 dr	13.6719 gr
1 dr	27.3438 gr
2 dr	54.6875 gr
5 dr	136.7188 gr
10 dr	273.4375 gr
16 dr	437.5 gr
25 dr	683.5938 gr
50 dr	1,367.1875 gr
100 dr	2,734.375 gr
256 dr	7,000 gr
500 dr	13,671.875 gr
1,000 dr	27,343.75 gr

Good to Know About Drams to Grains Conversion

The avoirdupois system's internal arithmetic is revealing: 7,000 grains per pound, 16 drams per ounce, 16 ounces per pound. These numbers were not chosen for mathematical harmony but for practical convenience at different scales. The grain suited jewelers and pharmacists; the dram suited spice merchants; the ounce and pound suited general trade. Each level of the system was optimized independently, creating the fractional relationships that make imperial arithmetic notoriously difficult.

Drams to Grains: What You Need to Know

A rifle bullet weighing 150 grains is about 5.49 drams. Gunpowder charges of 40 grains equal about 1.46 drams. Before the dram fell out of use, gunsmiths might have specified both in the same document. Today, ammunition uses grains exclusively, but the conversion remains useful for interpreting historical firearms specifications that mixed drams and grains.

What is a Dram? dr

A dram (avoirdupois) is a unit of mass equal to 1/16 of an ounce or 1/256 of a pound (1.7718451953125 grams). Historically used in pharmacy and old cooking recipes.

Imperial historical pharmacy old recipes whisky measurement

Learn more about Dram →

What is a Grain? gr

A grain is a unit of mass equal to exactly 64.79891 milligrams. It is the same in the avoirdupois, troy, and apothecaries' systems, derived from the 1959 international agreement defining the pound as exactly 0.45359237 kilograms.

Imperial Troy Apothecaries ammunition weight bullet measurement historical pharmacy

Learn more about Grain →

Going the other way? Use our Grains to Drams converter.

Drams to Grains FAQ

One avoirdupois dram contains exactly 27.34375 grains. This comes from the avoirdupois system: 7,000 grains per pound, 256 drams per pound, so 7,000 / 256 = 27.34375.
Because the grain and dram were standardized independently within the avoirdupois system. The grain was set at 1/7,000 of a pound, and the dram at 1/256 of a pound. Their ratio (7,000 / 256) does not produce a whole number, reflecting the system's organic evolution rather than deliberate mathematical design.
The grain remains actively used in ammunition manufacturing and some pharmaceutical contexts. The dram is largely obsolete, surviving only in a few specialized references. The grain has outlived the dram because it serves indispensable niches.

Non-Frequently Asked Questions About Drams to Grains

Questions nobody should ask - but someone did.

The grain found irreplaceable roles: bullet weights, powder charges, and pharmaceutical dosing all require grain-level precision. The dram was a convenience unit for market traders, easily replaced by ounces or grams. Units survive when they serve a function that no other unit fills. The grain is essential; the dram is redundant.
It competes with several other awkward avoirdupois ratios. 437.5 grains per ounce and 5,760 grains per troy pound are similarly inelegant. The entire avoirdupois system evolved organically over centuries, with each relationship reflecting a different historical compromise. Mathematical beauty was never the goal; practical commerce was.
No medieval balance could resolve to such precision. A merchant weighing 'one dram' would get approximately 27 grains, give or take a grain. The fractional 0.34375 grains (about 22 milligrams) was beneath the detection threshold of any scale available before the 19th century. The exact ratio is a modern mathematical calculation, not a historical measurement reality.