Short answer
Melt value = weight × (karat ÷ 24) × spot price per unit. In grams that is grams × (karat ÷ 24) × (spot per troy ounce ÷ 31.1034768).
The result is the metal’s melt value. A refiner, jeweler or pawn shop pays a percentage of it. That percentage is an estimate of a typical band, not a promise. The method is written up on the methodology page.
People say “scrap value” for two different numbers. The first is melt value: what the pure gold would be worth at the spot price if you could sell pure metal with no costs. The second is the payout: what a buyer will actually write a cheque for after testing, refining and their margin.
Keep those apart. If you only remember melt value, almost every honest offer will look low. If you only remember a payout percentage, you have nothing to compare shops against. Calculate melt first. Then apply a buyer band, and treat the band as a range that moves.
You need three inputs: weight of the gold, purity as a karat or a fineness stamp, and the spot price for one troy ounce. Everything else on this page is a way of getting those three inputs into the same units.
The formula
Purity is a fraction of pure gold. Karat gold uses 24 as the whole, so the fraction is karat divided by 24. Ten karat is 10 ÷ 24. Fourteen karat is 14 ÷ 24. Twenty-four karat is 24 ÷ 24, which is the pure-gold line the spot price already describes.
Multiply the gross weight by that fraction and you have the pure-gold weight. A 10 gram 14K chain does not contain 10 grams of gold. It contains 10 × 14 ÷ 24 grams of gold, and the rest is alloy: copper, silver, zinc or nickel, depending on the colour.
The spot price is quoted for one troy ounce, not for one gram and not for the kitchen ounce. Divide the troy-ounce price by 31.1034768 to get a price per gram. Multiply the pure-gold weight in grams by that price per gram. That product is the melt value.
The same product in one line: grams × (karat ÷ 24) × (spot per troy ounce ÷ 31.1034768). If your scale speaks pennyweights, convert to grams first, or divide the troy-ounce price by 20, because one troy ounce is 20 pennyweights. Both paths meet if the conversion factors stay exact.
A fineness stamp instead of a karat
A stamp such as 585, 750 or 916 is parts per thousand, not a karat. Divide the stamp by 1,000 and use that fraction in place of karat ÷ 24. A 750 stamp is 0.750, the same idea as 18 ÷ 24. On this site a custom purity of 100 or less is read as a percent, and 101 to 1,000 is read as fineness. That rule is on the methodology page and in the dental calculator, where a crown has no default karat.
Do not run a plated or gold-filled piece through the solid-karat formula. “1/20 12K GF” means a thin layer, not a 12K object. Use the gold-filled calculator for those marks. The gold purity chart lists the solid-karat stamps beside the plated ones.
Step by step
Six steps cover a normal lot of solid karat jewelry. Skip a step and the number looks precise while the input is wrong.
- 1. Identify the karat Read the stamp: 10K, 14K, 18K, 22K, or a fineness such as 417, 585, 750 or 916. Sort the lot. A 10K chain and an 18K ring are two lines, not an average. If a piece has no stamp, set it aside for a test. Guessing 14K because “most rings are 14K” is how offers disappoint.
- 2. Weigh in grams or pennyweights Use a scale that reads at least 0.1 gram, and tare the tray. Weigh gold, not the box, the pouch or a stone you can pop out. Write the unit next to the number. A “10” with no unit is not a weight.
- 3. Take the spot price Use the price the calculator is showing, and notice whether the badge says Live, Sample or Custom. A typed price is your scenario, not the market. Note the time if you are about to walk into a shop. The shop’s board will not match a quote from yesterday.
- 4. Compute the pure-gold weight Multiply grams by karat ÷ 24, or by fineness ÷ 1,000. This is the only gold the rest of the formula pays for. Alloy weight is real on the scale and worth little next to gold.
- 5. Multiply by the price per unit Pure grams times the spot price per gram is the melt value. Keep full precision until the end, then round money to the usual minor unit, two places for US dollars.
- 6. Apply a buyer percentage Melt value is the ceiling in a scrap sale. A mail-in refiner, a local jeweler and a pawn shop sit in different bands because their costs differ. The bands on the scrap gold calculator are labelled estimates. How those buyers differ is covered in where to sell scrap gold.
Units
Gold prices use the troy ounce. Kitchen scales and food labels use the avoirdupois ounce, the regular ounce. They are not the same. Using the regular ounce as if it were a troy ounce overstates the weight of a true troy ounce of gold, and it understates how many grams sit in the price quote. The factors below are the ones the calculators use.
| Unit | Grams | How it shows up |
|---|---|---|
| Troy ounce | 31.1034768 g | The unit of the spot price. Twenty pennyweights. |
| Regular ounce | 28.349523125 g | Kitchen and postal ounces. Lighter than a troy ounce. |
| Pennyweight (dwt) | 1.55517384 g | Common on US jewelry scales and buyer tickets. |
| Gram | 1 g | The easiest unit if you convert the spot price per gram. |
Troy ounce versus regular ounce
A troy ounce is 31.1034768 grams. A regular ounce is 28.349523125 grams. The troy ounce is heavier. If a listing says “per ounce” next to a gold price, it almost always means troy, but a household scale in “oz” mode means the lighter one. Mixing them is a quiet way to miss by about 10 percent.
Pennyweight is the jeweler’s step between grams and troy ounces. One pennyweight is 1.55517384 grams. Twenty pennyweights make a troy ounce. If a buyer says “$ per dwt,” they have already folded purity and their margin into that figure, or they have not. Ask which. A price per pennyweight of pure gold is not a price per pennyweight of 14K.
The gold weight calculator is for when you know a ring size or a chain length and not a scale weight. Treat that result as an estimate of weight, then run it through the melt formula. An estimated weight plus an estimated purity is a wide range, not a single cheque.
Worked example
The page does not store a gold price. The box below keeps the formula in symbols until the shared price store fills the amount. Refreshing the price changes the dollars. It does not change the 10 grams or the 14 karat.
Worked example. Ten grams of 14K gold, written with symbols until the price store answers:
10 g × (14 ÷ 24) × (spot per troy ounce ÷ 31.1034768)
The amount fills in from the same price the calculators use. It is not written into this page.
Read the badge. Live means the feed answered. Sample means the site is showing its fallback figure because the feed did not. Custom means someone typed a price. Compare shops against the same kind of price, taken at the same time. A sample figure is for learning the steps, not for arguing with a buyer’s board.
Stones, clasps and solder
Scales weigh whatever you put on them. A diamond, a glass stone, a steel earring post and a lobster clasp all add grams that are not gold. Buyers know this. They will pop stones, or they will deduct a fixed amount, or they will weigh the piece and then test a filing. If you can remove a stone without damaging a piece you might keep, the gold weight is clearer. If you cannot, expect the payout to be based on a lower gold weight than the scale shows.
Clasps are a small but real leak. Some spring rings are gold of a lower karat than the chain. Some are base metal with a gold wash. A magnetic clasp is a hint of steel, not a verdict on the chain. Weigh the chain and the clasp separately when you can, and do not assign the chain’s karat to a clasp you have not read.
Solder is the metal that joins links and ring shanks. It has to melt at a lower temperature than the jewelry, so it is not the same alloy as the piece. Old repairs can be a visible blob of a different colour. In a heavy repair the solder is a few percent of the weight and only partly gold. For a normal chain it is noise next to a wrong karat. For a ring that has been sized three times, mention it, and do not be surprised if the assay comes in a little under the stamp.
Hollow, filled and dental
Hollow beads and rope chains are still karat gold if they are stamped as such. They are light, so the melt value is light. Gold-filled and rolled-gold plate are a layer bonded to base metal. The stamped fraction, such as 1/20, is the gold alloy’s share of the weight, and that alloy is itself only partly gold. Dental crowns are often a white or yellow alloy with no karat stamp. Price them from a tested purity, using the dental gold calculator, and remember the site does not price platinum-group metals that sometimes sit in dental alloy.
Melt value and what a buyer pays
Spot price is a wholesale market for large, known bars. Your chain is not that. Someone has to check the karat, melt the lot, refine the alloy and sell the resulting metal. Each step has a cost, and the buyer keeps a margin. That is why a fair scrap offer is a percentage of melt, not the melt figure itself.
The bands on this site are the ones in the scrap calculator: mail-in refiners toward the top of the range, local jewelers in the middle, pawn shops toward the bottom. They are typical ranges, they vary by lot size and by the day, and they are not a quote from any named shop. A two-gram earring will not get the same percentage as a kilo of 18K. A buyer who does not assay will pay less because they are guessing.
Take the melt value from the calculator into the shop. Ask what gold price they are using, what karat they assigned, what weight they recorded, and what percentage that implies. An offer with no weight and no karat is a number you cannot check. The comparison is the point of where to sell scrap gold.
Common mistakes
- Using the regular ounce where the price is per troy ounce.
- Averaging 10K and 18K into “about 14K” and weighing them as one pile.
- Trusting a worn “14K” stamp on a piece that also says GF, GP or HGE.
- Forgetting that 585 is close to 14K but not the same arithmetic as 14 ÷ 24.
- Weighing stones, and then feeling cheated when the buyer removes them.
- Comparing today’s shop offer with a spot price from last month.
- Treating melt value as the amount a buyer must pay, or as an appraisal.
- Running gold-filled scrap through the solid-karat formula and expecting jewelry prices.
If the piece might be worth more as a ring than as metal, stop before you scrap it. Maker’s marks, intact stones and unusual age are invisible to the melt formula. The formula is doing its job. It is only pricing gold.
Use the scrap calculator
The calculator below is the same tool as the scrap gold calculator on the home page. Add each karat as its own line, set the unit, and read melt value beside a payout band. The band is an estimate. The offer box is there so you can compare a number a buyer gave you. Neither line is an offer from this site. We do not buy gold.
Your Gold Piece
1 troy oz = 31.1 g · 1 oz = 28.35 g · 1 dwt = 1.555 g
- 58.3% pure · 5.83 g gold · —
Questions
What is the formula for scrap gold value?
Melt value equals the weight in grams, times karat divided by 24, times the spot price per gram. The price per gram is the troy-ounce price divided by 31.1034768. A buyer then pays a percentage of that melt value.
Should I weigh in grams or pennyweights?
Either works if you convert correctly. One pennyweight is 1.55517384 grams. Many US buyers quote in pennyweights. Grams are easier to check on a kitchen scale. Do not mix the two in one multiplication.
Is 14K exactly 58.5 percent gold?
Fourteen divided by 24 is about 58.3 percent, or 583 parts per thousand. A 585 stamp means 58.5 percent. The difference is small. This site prices karat gold as karat divided by 24 and says so on the karat pages.
Do stones and the clasp count?
They count on the scale and they do not count as gold. Weigh the metal you are selling, or expect the buyer to deduct stones, steel springs and a heavy clasp. Solder is only partly gold.
Why is the offer below the melt value?
Melt value is the metal at the spot price. Refining, assay, shipping and the buyer’s margin come out of that number. The scrap calculator shows typical bands. They are estimates, not a quote.
Does a broken chain lose scrap value?
Breaks do not change the gold content. A broken chain, a single earring and a bent ring are priced by weight and karat. A signed, antique or stone-set piece can be worth more as jewelry than as scrap.
Is a melt value an appraisal?
No. An appraisal describes a specific piece for insurance or sale and is done by an appraiser who can see it. A melt value ignores stones, maker and condition. It is an estimate, not an offer and not advice.
What if there is no karat stamp?
Do not guess a high karat. Use the gold karat calculator only after a test, or ask a jeweler to test the piece. Plated and gold-filled items use a different, much smaller gold fraction.
This is a melt-value estimate, not an appraisal or an offer.