How many scruples are in one pennyweight?

One pennyweight equals exactly 1.2 scruples. This clean ratio exists because both units are defined in grains: 24 grains per pennyweight and 20 grains per scruple. 24 divided by 20 equals 1.2 exactly.

Why is this ratio so clean compared to other conversions?

The pennyweight and scruple share the grain as their common foundation. Both the troy and apothecary systems use the identical grain (64.79891 mg), making conversions between them simple ratios of whole-number grain counts. This shared root is the reason their ratio is an exact decimal rather than an approximation.

Are both units still in use?

The pennyweight remains active in North American precious metals and jewelry trading. The scruple has largely fallen out of pharmaceutical use since the adoption of the metric system in modern pharmacy, though it persists in historical references and some herbal medicine traditions.

Pennyweights to Scruples (dwt to s ap) Converter

1 dwt = 1.2 s ap

1 Pennyweight equals 1.2 Scruples (1 dwt = 1.2 s ap). Convert Pennyweights to Scruples with formula, table, and examples.

One pennyweight equals exactly 1.2 scruples. Both units belong to weight systems rooted in medieval commerce: the pennyweight from the troy precious metals tradition and the scruple from the apothecary pharmaceutical tradition. Their clean 5-to-6 ratio reflects shared ancestry in the grain, where both are defined as exact multiples of grains (24 grains per pennyweight, 20 grains per scruple).

How to Convert Pennyweights to Scruples

s ap = dwt × 1.2

Multiply the value in Pennyweights by 1.2

Take your value in Pennyweights
Multiply by 1.2
Read the result in Scruples

Common Pennyweights to Scruples Conversions

Pennyweights (dwt)	Scruples (s ap)	Status
0.5 dwt	0.6 s ap
1 dwt	1.2 s ap
2 dwt	2.4 s ap
5 dwt	6 s ap
10 dwt	12 s ap
20 dwt	24 s ap
50 dwt	60 s ap
100 dwt	120 s ap
200 dwt	240 s ap
240 dwt	288 s ap
500 dwt	600 s ap
1,000 dwt	1,200 s ap
5,000 dwt	6,000 s ap

Good to Know About Pennyweights to Scruples Conversion

The pennyweight and scruple represent the two branches of pre-metric English weight that diverged for different industries. The troy branch (pennyweight, troy ounce) served goldsmiths and mints, while the apothecary branch (scruple, dram, apothecary ounce) served pharmacists and physicians. Both grew from the same grain root, like linguistic cognates that share an ancestor but evolved different meanings in different contexts.

Pennyweights to Scruples: What You Need to Know

Historical pharmacy and alchemy manuscripts sometimes reference both pennyweights and scruples when describing preparations that combined precious metals with pharmaceutical compounds. Mercury-based medicines, gold-infused elixirs, and silver nitrate preparations appear in texts where the metallic ingredient is weighed in pennyweights and the pharmaceutical components in scruples.

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 Scruple? s ap

An apothecary scruple equals 20 grains or 1/3 of a dram apothecary (1.2959782 grams). A historical pharmaceutical unit largely replaced by metric measurements.

Apothecaries historical pharmacy historical medicine

Learn more about Scruple →

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

Pennyweights to Scruples FAQ

One pennyweight equals exactly 1.2 scruples. This clean ratio exists because both units are defined in grains: 24 grains per pennyweight and 20 grains per scruple. 24 divided by 20 equals 1.2 exactly.
The pennyweight and scruple share the grain as their common foundation. Both the troy and apothecary systems use the identical grain (64.79891 mg), making conversions between them simple ratios of whole-number grain counts. This shared root is the reason their ratio is an exact decimal rather than an approximation.
The pennyweight remains active in North American precious metals and jewelry trading. The scruple has largely fallen out of pharmaceutical use since the adoption of the metric system in modern pharmacy, though it persists in historical references and some herbal medicine traditions.

Non-Frequently Asked Questions About Pennyweights to Scruples

Questions nobody should ask - but someone did.

In the apothecary-weight sense, 1.2 scruples is indeed exactly one pennyweight. In the moral sense, 1.2 scruples represents a level of conscience that is present but not overwhelming, perhaps sufficient to make you hesitate at a yellow traffic light but not enough to prevent you from jaywalking on an empty street.
Quite a few, actually. Apothecaries in medieval and early modern Europe often dealt in a wide range of goods, including gold leaf for gilding medicines, mercury, and other metallic substances. Such practitioners genuinely needed to convert between pennyweights and scruples as part of their daily work.
It is certainly one of the cleanest. Most cross-system conversions produce long decimal numbers, but the pennyweight-to-scruple ratio of exactly 1.2 is elegant enough to be calculated by a medieval merchant in their head. It ranks alongside the 24-grains-per-pennyweight and 16-ounces-per-pound ratios for simple mathematical beauty.