Pennyweight conversions
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| From | To | Multiply by |
|---|---|---|
| Pennyweights | Grams | 1.55517384 |
| Grams | Pennyweights | 0.643014931 |
| Pennyweights | Troy ounces | 0.05 |
| Troy ounces | Pennyweights | 20 |
| Pennyweights | Grains | 24 |
| Pennyweights | Standard ounces | 0.0548571 |
A quick reference table
Swipe the table sideways to see every column
| Pennyweights | Grams | Troy ounces | 14K melt value |
|---|---|---|---|
| 1 | 1.555 | 0.050 | $118.77 |
| 2 | 3.110 | 0.100 | $237.54 |
| 5 | 7.776 | 0.250 | $593.85 |
| 10 | 15.552 | 0.500 | $1,187.70 |
| 20 | 31.103 | 1.000 | $2,375.39 |
| 50 | 77.759 | 2.500 | $5,938.48 |
Why this unit still exists
The troy system reached England in the fourteenth century and became the standard for coinage and precious metals. A pennyweight was, literally, the weight of a silver penny — 24 grains, one twentieth of a troy ounce. Coinage moved on; the trade did not. American jewelers, refiners and pawnbrokers still price in dwt because a market quoted per troy ounce divides into twentieths without leaving a remainder anyone has to think about.
Grams took over everywhere else, including retail scales and most consumer-facing pricing, which is why the two units now sit awkwardly side by side in the same transaction. Your scale says grams; the buyer's offer says pennyweights.
Comparing a dwt quote against a gram quote
This is the practical reason the unit matters. Suppose one shop offers $45 per gram for 14K and another offers $68 per pennyweight. The second number is bigger, and it is also worse: $68 ÷ 1.55517 = $43.72 per gram.
The calculator above does this automatically — enter any weight in any unit and the result panel lists the equivalent in grams, pennyweights, troy ounces and standard ounces, along with the melt value per gram and per pennyweight at your chosen karat.
Watch the other ounce
Since pennyweights are defined against the troy ounce, it is worth repeating that a troy ounce is 31.1035 g and the household ounce on a postal scale is 28.3495 g. Twenty pennyweights make a troy ounce, not a regular one. Mixing them inflates an estimate by about 10%.
Pennyweight questions
What is a pennyweight?
A pennyweight, abbreviated dwt, is one twentieth of a troy ounce — exactly 1.55517384 grams. The abbreviation uses a d because it comes from the Latin denarius, the coin the medieval English penny descended from.
How many grams are in a pennyweight?
1.55517384 grams. Going the other way, one gram is 0.643 pennyweights. A rough mental check: multiply pennyweights by 1.5 and add a little.
How many pennyweights are in a troy ounce?
Exactly twenty. That is the definition of the unit, and it is why converting a per-dwt price to a per-ounce price is simply multiplying by 20.
Why do jewelers use pennyweights instead of grams?
Because a troy ounce divides into twenty pennyweights cleanly, which makes scrap lots easy to price and settle against an ounce-quoted market. The convention long predates metric scales in the US trade and has simply stuck.
Is a per-pennyweight price better than a per-gram price?
Neither is better — but a per-dwt number always looks about 55% larger than the same value expressed per gram, because the unit is heavier. Convert both to the same unit before you compare two offers.
How do I convert a dwt price to a per-gram price?
Divide by 1.55517384. A buyer quoting $70 per pennyweight is offering about $45.01 per gram at the same karat.