A coin’s melt value is the market value of the precious metal inside it. Working it out takes three facts about the coin and one price.
The three facts you need
- Gross weight: what the coin weighs when new, in grams. A pre-1965 US quarter weighs 6.25 g.
- Fineness: the share of that weight that is gold or silver. US silver coins are .900 (90%); the rest is copper.
- Troy ounce: precious metals are priced per troy ounce, which is exactly 31.1034768 grams.
The formula
Pure metal (troy oz) = gross weight (g) × fineness ÷ 31.1034768
Melt value = pure metal (troy oz) × spot price per troy oz
Example 1: a silver Washington quarter
A 1932–1964 Washington quarter weighs 6.25 g and is 90% silver.
- 6.25 g × 0.900 = 5.625 g of pure silver
- 5.625 g ÷ 31.1034768 = 0.1808 troy oz
- At a silver price of $50.00 per troy oz, the melt value is 0.1808 × $50.00 = $9.04
Example 2: a 40% silver Kennedy half dollar
Kennedy halves dated 1965–1970 weigh 11.50 g and are 40% silver overall.
- 11.50 g × 0.400 ÷ 31.1034768 = 0.1479 troy oz
- At $50.00 silver: 0.14789 × $50.00 = $7.39
A 1964 Kennedy half, at 90% silver and 12.50 g, holds 0.3617 troy oz, more than twice as much. The date matters.
Example 3: a $20 gold double eagle
US $20 gold pieces weigh 33.436 g and are 90% gold.
- 33.436 g × 0.900 ÷ 31.1034768 = 0.96749 troy oz
- At $4,000 gold: 0.96749 × $4,000 = $3,869.97
Things the formula leaves out
- Wear. The formula uses the coin’s new weight. A heavily worn coin can be a few percent lighter.
- Other metals. The copper in a silver coin is worth very little and is ignored.
- Not a price. Melt value is what the metal is worth at spot. It is not an offer to buy or sell.
- Collector value. Scarce dates, varieties and coins in high grades are often worth far more than melt.
Skip the arithmetic
Every coin page on JinglePig shows this calculation with today’s spot price, and the coin melt calculator adds up whole rolls, bags and mixed lots.