Pennyweights to Grams (dwt to g)

1 pennyweight equals 1.55517384 grams exactly.

1 pennyweight = 1.55517384 grams

How to convert pennyweights to grams

To convert pennyweights to grams, multiply the number of pennyweights by 1.55517384. This factor is exact. To go the other way, multiply grams by 0.6430149314 (rounded).

grams = pennyweights × 1.55517384

Example: 10 pennyweights = 15.5517384 grams.

About these units

Pennyweight (dwt)

Troy & apothecaries'Traditional unit (still used in some regions)

One twentieth of a troy ounce (1.5552 g), originally the weight of a silver penny. Still used by jewelers.

Silver pennies gave this unit its name. In the Middle Ages an English penny weighed one twentieth of an ounce and one 240th of a pound of sterling silver, so its weight and its face value agreed. The abbreviation dwt keeps the d from denarius, the Roman coin that stood behind the old British penny.

The size changed over time. Under the medieval Tower pound a pennyweight was 32 Tower grains. When troy weights replaced Tower weights in 1527, it became 24 troy grains, which is exactly 1.55517384 grams.

Twenty pennyweights make a troy ounce, and 240 make a troy pound. Jewellers still use it to work out the precious metal content of jewellery, and dental labs have used it for gold in crowns and inlays. In parts of England, gooseberry growers also record prize fruit in pennyweights and grains.

1 pennyweight = 0.00155517384 kilograms (exactly).

Sources: Wikipedia: Pennyweight; Wikipedia: Troy weight; NIST SP 811, Appendix B.8

Gram (g)

Metric (SI)Current unit

One thousandth of a kilogram. The standard unit for food quantities and small objects.

A gram was once defined as a small drop of the natural world. The French National Convention of 1795 set it as the absolute weight of a volume of pure water equal to a cube one hundredth of a metre on each side, a cubic centimetre. The reference temperature was first the melting point of ice and was later changed to the temperature of maximum density of water, about 4 degrees Celsius. The word came into French as gramme, from Late Latin gramma, itself from the Greek for a letter or small mark; in Late Antiquity it meant about one twenty-fourth of an ounce.

The gram was the base unit of mass in the centimetre-gram-second system, but in 1960 the SI took the kilogram as its base unit, which made the gram one thousandth of it. That is why it appears in so many everyday places: it is the standard for non-liquid ingredients in cooking and shopping, and nutrition labels commonly list contents per 100 g. For a sense of scale, a small paper clip or a pen cap weighs about a gram, and a Japanese 1-yen coin is close to exactly that, while a US penny is around 2.5 g.

1 gram = 0.001 kilograms (exactly).

Sources: Wikipedia: Gram; Wikipedia: Kilogram

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