How Gold Jewelry Is Priced: Karat, Weight & Spot Price
Every honest gold offer comes from three numbers: how pure the gold is, how much it weighs, and what gold is trading for today. Learn the arithmetic once and you will never wonder whether a quote is reasonable again.
- Karat tells you purity: 14K gold is 58.3% pure gold.
- Gold is weighed in grams; one troy ounce is 31.1 grams.
- Pure gold content × spot price = the metal value of your piece.
- Stones, clasps and non-gold parts do not count as gold weight.
Step one: karat is purity, not quality
Karat is a fraction out of 24. Pure gold is 24K, and everything below it is gold alloyed with other metals for strength and colour. The percentages that matter:
| Karat | Pure gold | Stamped |
|---|---|---|
| 10K | 41.7% | 417 |
| 14K | 58.3% | 583, 585 |
| 18K | 75.0% | 750 |
| 22K | 91.7% | 916 |
| 24K | 99.9% | 999 |
Multiply purity by gram weight and the day’s spot price and you have the melt value of the piece — the ceiling on what the metal is worth, before any buyer’s spread.
One wrinkle worth knowing: 14K is mathematically 583 parts per thousand, but European pieces are usually stamped 585 because they are alloyed slightly rich to guarantee the minimum. Both are 14K. A piece stamped 585 is not higher-karat than one stamped 583.
Step two: weight in grams, on a real scale
Jewelers weigh gold in grams or pennyweights, and precious-metal markets quote in troy ounces. One troy ounce equals 31.1 grams — not the 28.35 grams in the ounce on your kitchen scale, which is where a lot of online confusion starts.
Only the gold gets weighed. Diamonds, coloured stones, steel spring clasps, watch movements and enamel are removed from the calculation or physically removed from the piece. A gemstone may have its own value, but it is not gold value.
Grams, pennyweights and troy ounces
Three units are in play and they are not interchangeable. Getting them confused is the most expensive arithmetic mistake a seller can make.
| 1 troy ounce | 31.1035 grams — the unit gold markets quote in |
|---|---|
| 1 pennyweight (dwt) | 1.5552 grams — 1/20 of a troy ounce, still used by many US jewellers |
| 1 kitchen ounce | 28.3495 grams — avoirdupois, never used for precious metals |
Here is why it matters. If one buyer quotes you per pennyweight and another quotes you per gram, convert to a common unit before you compare anything — the bigger-looking number is not always the better offer.
Step three: do the math
The formula is simple: gram weight × karat purity × (spot price ÷ 31.1) = the pure gold value of your piece.
Say you have a 14K chain weighing 20 grams. Its pure gold content is 20 × 0.583, or about 11.66 grams. Multiply by that day’s gold price per gram and you have the metal value. Spot moves constantly — any real buyer will quote you against that day’s market.
Your offer will sit below that metal value, because the buyer has to refine the metal and stay in business. What you are judging is how far below, and whether the process was transparent enough for you to tell.
What comes off the weight before you are paid
Not everything on the scale is gold, and an honest buyer tells you what is being excluded rather than weighing the lot and discounting the total afterwards. Expect these to come out:
- Stones. Diamonds and coloured stones are not gold. They may carry real value of their own, quoted separately.
- Spring clasps and findings. Lobster clasps and spring rings usually contain steel mechanisms.
- Watch movements. The case may be solid gold; the movement is not.
- Enamel, resin and pearls. Neither metal nor payable weight.
- Plaster or pitch filling. Weighted sterling candlesticks and some holloware are filled. Gross weight is not metal weight.
Plated and gold-filled pieces are a different problem entirely. Gold-plated, gold-filled, rolled gold and vermeil carry a microscopic amount of gold bonded to a base metal, and they are not worth their weight in gold no matter what the stamp implies. Roma Jewelry tests unmarked and doubtful pieces free at the counter in Massapequa, because guessing in either direction costs somebody money.
When a piece is worth more than its gold
Sometimes the scale is the wrong tool. A signed designer piece, an Art Deco mounting, a collectible watch or a coin with a scarce date can be worth several times its melt value, and melting it would destroy that premium.
This is exactly why it pays to have jewelry looked at by a buyer who also sells jewelry. We flag pieces that are worth more intact — see our guides to estate and antique jewelry and coin values.
Common questions about gold pricing
How do I calculate the value of 14K gold per gram?
Divide the gold spot price by 31.1035 to get the price per gram of pure gold, then multiply by 0.583 for 14K. Multiply by the gram weight of your piece for its melt value. Roma Jewelry quotes against that day’s spot at the counter in Massapequa.
Is 585 gold better than 583 gold?
No — both are 14K. The mathematical purity of 14K is 583 parts per thousand, but European manufacturers commonly stamp 585 because they alloy slightly rich to guarantee the minimum. The difference is fractions of a percent and does not change what a buyer pays per gram.
How many grams are in a pennyweight of gold?
One pennyweight (dwt) is 1.5552 grams, or one twentieth of a troy ounce. Convert competing offers to the same unit before you compare — a bigger-looking number in dwt is not always the better offer in grams.
Why is a troy ounce different from a normal ounce?
A troy ounce is 31.1035 grams and is the standard unit for precious metals. The avoirdupois ounce on a kitchen scale is 28.3495 grams. Using the wrong one overstates a gold weight by about 9.6%, which is the single most common source of confusion when sellers try to value gold at home.
Will a gold buyer pay the full melt value?
No, and any buyer claiming to should be treated with suspicion. Melt value is the market value of the metal — the ceiling. The buyer carries refining costs, overhead and the risk of the price moving before the metal is sold, and that comes out of the spread. Roma Jewelry quotes against the day’s spot price and shows the karat and weight so you can see where the offer sits.
Does gold-plated jewelry have any scrap value?
Almost none. Gold-plated, gold-filled, rolled gold and vermeil carry a microscopic layer of gold bonded to a base metal, so they are not worth their weight in gold whatever the stamp suggests. Roma Jewelry tests unmarked and doubtful pieces free at the counter in Massapequa, because guessing in either direction costs somebody money.