How this instrument works
Scrap gold is jewelry, coins, or dental work sold not for its design but for the metal it contains — a mismatched earring, a broken chain, a ring that no longer fits. The person running these numbers is usually standing at a pawn counter or a cash-for-gold shop, not a refinery, which is why this instrument works in grams and whole-number percentages: the units a jewelry scale and a hallmark stamp actually use, rather than the troy ounces and decimal fractions bullion traders quote.
Purity here is read straight off the hallmark, then typed in as a percentage rather than converted first. A piece stamped 24K is about 99.9% pure gold, 22K is 91.6%, 18K is 75%, 14K is 58.3%, and 10K is 41.7% — the remainder in every case is copper, silver, or zinc added for hardness, and it carries no scrap value at all. Twenty-two karat is the purity most common in jewelry sold across South Asia and the Gulf, which is why the default figures on this page use 91.6%.
The number this instrument returns is the value of the gold content alone, calculated as if every gram entered converts to cash at the full spot rate. A real buyer offers less, because the piece still has to be tested with acid, a touchstone, or an X-ray fluorescence gun, separated from stones and solder, melted, and refined before the metal is liquid — costs and risk the buyer's discount is covering. Treat the figure here as a ceiling to compare offers against, not a guaranteed payout.
- Weigh the piece on a gram scale and enter the total under Weight, grams.
- Type the purity percentage from a hallmark or an assay test into Purity, % (e.g. 91.6% for 22K).
- Enter today's quoted rate, in dollars per gram, under Gold spot price, $/gram.
- Read Scrap value, $ — the dollar value of the gold content alone, before any buyer's margin.
Worked example — 10 grams of 22-karat gold
Set Weight, grams to 10, Purity, % (e.g. 91.6% for 22K) to 91.6, and Gold spot price, $/gram to 65. The instrument multiplies 10 × 0.916 × 65 and returns a Scrap value of $595.40 — the price of the actual gold locked inside that ten-gram piece.
The same ten grams at 24-karat purity (99.9%) would compute to 10 × 0.999 × 65 = $649.35 instead. The $53.95 gap between the two figures is what 8.4 percentage points of alloy — copper or silver mixed in purely for strength — is worth to a scrap buyer weighing melted metal: nothing.
Questions
Why would a scrap buyer pay less than the number this calculator shows?
This figure is the gold content's raw value at full spot price, with zero cost assumed. A real buyer subtracts a margin — commonly somewhere between 10% and 30% — to cover testing, melting, refining fees, and their own profit before the metal ever reaches a refinery. A cash offer landing under $595.40 on the ten-gram example above is not necessarily a lowball; it means the shop's costs are already built into the number. Use this figure as the ceiling to weigh competing offers against.
What if a necklace has a clasp made from a different karat than the chain?
Weigh and test each part separately, because the formula assumes one uniform purity across the whole Weight, grams entry. An 18K clasp soldered onto a 22K chain has to be entered as two smaller weights at two different Purity, % figures and added together — lumping them into a single weight at one karat overstates or understates the true gold content depending on which piece is heavier.
Why type in a percentage instead of a karat number?
Karat is a 24-part fraction — 22K means 22 parts gold out of 24 — handy for stamping a piece but awkward to multiply directly, so this page wants the same information as a percent: 91.6% for 22K, 75% for 18K, 58.3% for 14K, 41.7% for 10K. Gram-denominated scrap markets outside the US routinely print purity as a percentage on the buyer's receipt for the same reason.
Does the weight I enter need to exclude stones or a plated shell?
Yes, ideally. Every gram typed into Weight, grams is treated as gold at the stated purity, so a diamond, a steel spring clasp, or a gold-plated shell inflates the result if the whole item is weighed together. A buyer will usually pry loose or estimate the weight of stones and non-gold fittings before testing what remains, and a plated piece can be worth little once the base metal underneath is exposed.
Why is the spot price entered per gram instead of per troy ounce?
Because that matches how a jewelry or pawn scale actually weighs a ring or a chain, and how most of the world's scrap trade quotes gold — grams, not the troy ounce (31.1035 g) that bullion and futures markets use for bars and coins. Pasting a per-ounce quote straight into Gold spot price, $/gram without dividing by 31.1035 first understates the scrap value roughly thirty-one times over.
Is a mixed batch of old jewelry worth entering as one total weight?
Only if every piece shares the same purity, which is rare — a drawer of old jewelry usually mixes 10K, 14K, and 22K pieces with different alloy content. Weighing the whole pile at once and typing in a single guessed or averaged Purity, % figure misprices the batch; sorting by karat first and running each group through the calculator separately gives a far more accurate total.
References
- IRS Topic No. 409 — Capital Gains and Losses on collectibles
- FTC Consumer Advice — consumer protection resources
Read this first: This instrument shows arithmetic, not advice. Real offers add fees, taxes and terms that vary by lender and place — verify the figures against your actual paperwork before deciding anything.