How to calculate the gold value of jewellery by weight and karat
Short answer: the metal value of a gold item is its gold weight in grams, multiplied by its fineness (the share of pure gold), multiplied by today's price of one gram of fine gold. Everything else, such as stones, workmanship and brand, is a separate question.
The formula
Metal value = grams × fineness ÷ 1000 × price per gram of fine gold
Fineness is written in parts per thousand and is usually stamped on the item as a hallmark:
| Karat | Fineness (‰) | Pure gold share |
|---|---|---|
| 9k | 375 | 37.5% |
| 10k | 417 | 41.7% |
| 14k | 585 | 58.5% |
| 18k | 750 | 75.0% |
| 22k | 916 | 91.6% |
| 24k | 999 | 99.9% |
A worked example
A 14k chain weighs 10 grams. If fine gold costs 130 per gram in your currency, the metal value is 10 × 585 ÷ 1000 × 130 = 760.50. Your loan or purchase offer is then a percentage of that figure, set by your own shop policy.
What not to put on the scale
- Stones. A diamond or a zircon adds weight but no gold. Weigh the gold only, or deduct the stones.
- Steel parts. Springs in clasps and some bracelet links are steel, not gold.
- Mixed metals. Two-tone items can contain silver or other alloys outside the stamped part.
Which gold price to use
Use an official, dated reference price and write the date next to the calculation. A price that changes during the day is fine for trading, but at the counter a single reference price per day keeps every clerk consistent and every receipt explainable. PawnMeter uses an official central bank reference price, converted to your currency at the same day's official rate, and shows the date on every result.
Check the hallmark, then the metal
A stamp says what the maker claims. Hallmarks can be worn, foreign or fake, so the usual practice is to test the metal as well (acid test, electronic tester or XRF) before relying on the stamped fineness.
How PawnMeter does it
The clerk enters the gold weight and the karat. PawnMeter shows the metal value, the reference price and its date, and the offer at the shop's own percentage, so the same chain gets the same number at every counter.
PawnMeter: Type the item. PawnMeter shows the resale price and a suggested loan, calculated only from what comparable items really sold for. When there is not enough data, it says so instead of guessing.
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