Pennyweight (DWT) Silver Calculator

What Is a Pennyweight (DWT)?

A pennyweight (DWT) is a unit of mass used almost exclusively in the jewelry and precious-metals trade. One pennyweight equals exactly 1.55517 grams, or 1/20 of a troy ounce (0.05 troy oz). It is the unit most US jewelers, pawnbrokers, and refiners reach for when they weigh and price scrap gold and silver, so if you walk into a shop with old sterling and the counter quotes you a "price per DWT," this is the number they mean.

The name is literal. The abbreviation DWT stands for "denarius weight" - the denarius was the Roman silver coin that became the English penny. In medieval England a single silver penny was struck to weigh exactly one twentieth of a troy ounce, so 20 pennies physically weighed one troy ounce and 240 pennies made one troy pound. That is why a pennyweight is still 1/20 of a troy ounce today: it really was once the weight of a silver penny.

DWT to Grams and Troy Ounces: Exact Conversions

Every pennyweight conversion comes from two fixed constants. Memorize these and you can check any jeweler's math:

• 1 DWT = 1.55517 grams
• 1 DWT = 0.05 troy ounces (exactly 1/20 ozt)
• 20 DWT = 1 troy ounce = 31.1035 grams
• 1 gram = 0.643015 DWT
• 1 troy ounce = 20 DWT
• 1 DWT = 0.05486 regular (avoirdupois) ounces

DWT to Grams Conversion Table

• 1 DWT = 1.56 g = 0.05 ozt
• 5 DWT = 7.78 g = 0.25 ozt
• 10 DWT = 15.55 g = 0.50 ozt
• 12 DWT = 18.66 g = 0.60 ozt
• 15 DWT = 23.33 g = 0.75 ozt
• 20 DWT = 31.10 g = 1.00 ozt
• 25 DWT = 38.88 g = 1.25 ozt
• 50 DWT = 77.76 g = 2.50 ozt
• 100 DWT = 155.52 g = 5.00 ozt

Grams to DWT (the reverse direction)

If your scale reads grams and the buyer pays per pennyweight, divide grams by 1.55517 (or multiply by 0.643). For example: 31.1 g / 1.55517 = 20 DWT; 50 g x 0.643 = 32.15 DWT; 100 g = 64.3 DWT. A common chain weighs about 10 g, which is roughly 6.43 DWT.

Why Jewelers Use Pennyweight Instead of Grams

Pennyweight survives in the US jewelry trade for three practical reasons. First, tradition and tooling: bench jewelers' scales, casting weight tables, and findings catalogs have used DWT for over a century, and casting houses still quote metal in pennyweight. Second, convenient size: at 1.555 g, a pennyweight is granular enough to price small items like a ring or a pair of earrings without dealing in fractions of a troy ounce. Third, margin: quoting "$X per DWT" makes an offer feel small and tidy, while the same number per gram or per troy ounce can look very different to a seller. Knowing the conversion is exactly how you keep an offer honest.

How to Weigh Jewelry at Home

You do not need a jeweler's scale to get a reliable weight. A digital kitchen scale or a small pocket scale works, but accuracy matters because silver is sold by weight:

• Use a scale that reads to 0.1 g or finer. Most kitchen scales round to 1 g, which can throw a small ring's value off by 10-20%. A $10 pocket jewelry scale that reads to 0.01 g is a worthwhile buy if you sell often.
• Tare (zero) the scale with nothing on it, then place the item directly on the platform. If you use a small dish, place the empty dish first and press tare so its weight is subtracted.
• Remove non-silver parts. Gemstones, glued-in pearls, steel clasps, watch movements, and stainless spring bars are not silver and should be excluded or estimated out. Knife handles and weighted candlestick bases are filled with cement or pitch and must be subtracted entirely.
• Weigh in grams, then convert. Grams are the most universal reading. Convert to DWT only when you need to match a buyer's per-pennyweight quote.

The Pennyweight Silver Value Formula

The melt value of any silver item weighed in pennyweight is:

Value = DWT x 0.05 x purity x spot price

Here 0.05 converts pennyweight to troy ounces, purity is the silver fineness as a decimal (sterling = 0.925, fine = 0.999), and spot price is the current silver price per troy ounce. The calculator at the top of this page runs this exact formula live against the spot price.

Worked Examples

Assume a silver spot price of $32.00 per troy ounce for these examples (your live result above uses the real-time price):

• 12 DWT of sterling (925): 12 x 0.05 x 0.925 x $32.00 = $17.76 melt value. (12 DWT is also 18.66 g.)
• 20 DWT of sterling (one troy ounce): 20 x 0.05 x 0.925 x $32.00 = $29.60.
• 20 DWT of fine .999 silver: 20 x 0.05 x 0.999 x $32.00 = $31.97 - essentially full spot, because the item is nearly pure.
• 50 DWT of sterling flatware: 50 x 0.05 x 0.925 x $32.00 = $74.00.

What Jewelers Pay Per DWT vs Melt Value

Melt value is the theoretical full metal value. What a buyer actually pays is melt value minus their margin. For scrap sterling, typical real-world payouts run:

• Refiners (bulk, by mail): 90-97% of melt for large lots, after an assay and refining fee.
• Local coin and jewelry shops: 70-85% of melt for walk-in scrap sterling.
• Pawn shops: often 50-70% of melt, sometimes lower.

So if 20 DWT of sterling has a $29.60 melt value, a fair shop offer is roughly $21-25, a strong refiner offer is $27-28, and a lowball pawn offer might be $15-18. Use the melt figure as your floor and negotiate up from there - never down.

Pennyweight FAQ

Related Calculators

Use our scrap silver calculator for a full valuation with dealer discount estimates, or the silver melt value calculator to learn how melt pricing works.