Worked examples
The single most common error is not the arithmetic, it is the weight. People estimate, and they estimate high, because gold feels heavier than it is when you are hoping. These are realistic weights for four ordinary items, priced at the current benchmark.
- A 14k wedding band, about 5 g: $411.31 at melt. A plain band is all metal, so the weight is honest. Wider and heavier bands run to 8 g.
- A 14k curb chain, 20 inch, about 14 g: $1,151 at melt. Chain is where most scrap weight sits. Weigh the clasp with it; it is the same gold.
- An 18k pair of hoops, about 6 g: $634.60 at melt. Hollow hoops weigh far less than they look. Do not estimate by size.
- A 10k class ring, about 11 g: $646.35 at melt. The stone is glass or synthetic and worth nothing. Expect a deduction for its weight.
Notice how little separates the 11 gram 10k ring from the 6 gram 18k hoops. Weight and purity pull in opposite directions constantly, which is why the stamp has to be read before anything is weighed.
Getting the inputs right
Read the stamp, not the colour. Rose, white and yellow gold of the same karat contain exactly the same amount of gold; the difference is copper against palladium or nickel in the alloy. White gold is often rhodium plated as well, which adds nothing to the melt and wears off in a few years.
Weigh on something that reads to 0.1 g. Kitchen scales that step in whole grams will round a 5.4 g band to 5 g, and on a 200 gram lot that rounding runs to real money. How to weigh gold at home covers tare, stones and what to do if you have no scale at all.
Then match the unit. A pennyweight is 1.555 g and a troy ounce is 31.1035 g, and neither is the ounce on a kitchen scale. Troy ounce against ounce is the one page worth reading before you compare two quotes.
From melt to an offer
The calculator prints the payout bands under the melt figure because that is the number you are actually going to be handed. A 14 gram 14k chain at $1,151 melt is a pawn shop offer of $575.84 to $691.00, and a refiner offer of $921.34 to $978.92. Both are legitimate businesses. They are just different trades.
Melt calculator questions
How does a gold melt calculator work?
It multiplies the weight you enter by the purity fraction of the karat you select, then by the spot price per gram. The only inputs that matter are the weight, the stamp and the current benchmark, which is why two honest calculators will always agree.
What weight should I enter for a ring with a stone?
The metal weight, not the total. If you cannot separate them, weigh the whole piece and expect the buyer to deduct. A small accent stone is a fraction of a gram. A large one can be several, and guessing in your own favour only makes the counter conversation worse.
Should I weigh in grams or pennyweight?
Whichever your scale reads in. The calculator converts either. What matters is that you do not enter a pennyweight figure while the unit is set to grams, which overstates the answer by 55%.
Can I calculate a mixed lot at once?
Not in one pass, and you should not want to. Weigh each karat separately and run each one. A buyer who averages a mixed lot down to the lowest karat present is costing you the difference, and doing it yourself in the calculator hides the same loss.
Is the calculator accurate enough to negotiate with?
Yes, for the metal value. The arithmetic is exact and the constants are the legal fineness standards. The uncertainty is in your scale and in whether the stamp is honest, not in the calculation.
Does the calculator work for silver and platinum?
Yes. Switch the metal and the purity list changes to that metal standards: 925, 900 and 999 for silver, 950 and 900 for platinum. The formula underneath is identical.