How many avoirdupois drams are in one pennyweight?

One pennyweight equals approximately 0.878 avoirdupois drams. The pennyweight (1.555 grams) is slightly lighter than the avoirdupois dram (1.772 grams), so each pennyweight converts to slightly less than one dram.

Why are pennyweights and drams from different systems?

The pennyweight belongs to the troy system developed for precious metals, originating from French trade fairs. The dram belongs to the avoirdupois system used for everyday goods, originating from Italian merchant practices. They evolved independently for different commercial purposes and were never intended to align.

Is either unit still in regular use?

The pennyweight remains active in the North American precious metals and jewelry trade. The avoirdupois dram has largely fallen out of everyday use, though it persists in the ammunition industry through 'dram equivalent' markings on shotgun shells and in some traditional pharmacy contexts.

Pennyweights to Drams (dwt to dr) Converter

1 dwt = 0.8777 dr

1 Pennyweight equals 0.8777 Drams (1 dwt = 0.8777 dr). Convert Pennyweights to Drams with formula, table, and examples.

One pennyweight equals approximately 0.878 avoirdupois drams. This conversion bridges two distinct historical weight systems: the troy pennyweight used for precious metals and the avoirdupois dram used for general commerce. Since both units are relatively small, they operate in similar magnitude ranges, making their relationship more intuitive than many cross-system conversions.

How to Convert Pennyweights to Drams

dr = dwt × 0.8777142857

Multiply the value in Pennyweights by 0.8777142857

Take your value in Pennyweights
Multiply by 0.8777142857
Read the result in Drams

Common Pennyweights to Drams Conversions

Pennyweights (dwt)	Drams (dr)	Status
0.5 dwt	0.438857 dr
1 dwt	0.877714 dr
2 dwt	1.755429 dr
5 dwt	4.388571 dr
10 dwt	8.777143 dr
20 dwt	17.554286 dr
50 dwt	43.885714 dr
100 dwt	87.771429 dr
200 dwt	175.542857 dr
240 dwt	210.651429 dr
500 dwt	438.857143 dr
1,000 dwt	877.714286 dr
5,000 dwt	4,388.571429 dr

Good to Know About Pennyweights to Drams Conversion

The pennyweight and the dram both trace their roots to ancient Mediterranean commerce but arrived in English through different routes. The pennyweight came via Norman French silver trading standards, while the dram traveled from the Greek drachma through Arabic dirham into medieval English apothecary practice. Their parallel existence in English measurement reflects the layered history of trade influence on the British Isles.

Pennyweights to Drams: What You Need to Know

Historical trade records from colonial America occasionally mixed troy and avoirdupois measurements in the same ledger, particularly when a merchant dealt in both precious metals and general goods. A silversmith who also sold spices might record silver in pennyweights and pepper in drams on adjacent pages. Understanding both units helps researchers interpret these blended commercial records.

What is a Pennyweight? dwt

A pennyweight is a unit of mass equal to 24 grains or 1/20 of a troy ounce (1.55517384 grams). Used in the jewelry trade for weighing precious metals.

Troy jewelry manufacturing precious metal trade goldsmithing

Learn more about Pennyweight →

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 →

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

Pennyweights to Drams FAQ

One pennyweight equals approximately 0.878 avoirdupois drams. The pennyweight (1.555 grams) is slightly lighter than the avoirdupois dram (1.772 grams), so each pennyweight converts to slightly less than one dram.
The pennyweight belongs to the troy system developed for precious metals, originating from French trade fairs. The dram belongs to the avoirdupois system used for everyday goods, originating from Italian merchant practices. They evolved independently for different commercial purposes and were never intended to align.
The pennyweight remains active in the North American precious metals and jewelry trade. The avoirdupois dram has largely fallen out of everyday use, though it persists in the ammunition industry through 'dram equivalent' markings on shotgun shells and in some traditional pharmacy contexts.

Non-Frequently Asked Questions About Pennyweights to Drams

Questions nobody should ask - but someone did.

Not catastrophically bad, since the units are only about 12 percent apart. Confusing them on a silver transaction would mean overcharging or undercharging by roughly one-eighth, which would upset a customer but not bankrupt either party. Confusing troy ounces and avoirdupois ounces, however, would produce a 10 percent error that could genuinely sour a business relationship.
Surprisingly, a dram of gold is worth slightly more, because the avoirdupois dram is heavier (1.772 g versus 1.555 g). The pennyweight contains about 12 percent less gold by mass. Of course, gold is rarely sold in drams, so this is a theoretical victory for the dram that it cannot actually collect.
A 17th-century apothecary would understand pennyweights, since the troy system was standard in medicine before the metric system arrived. They would not, however, appreciate being called a pharmacist, having their practice disrupted by a time traveler, or discovering that their carefully balanced dram weights would eventually be rendered obsolete by milligrams.