How much is 18K gold worth by weight?
These examples use 75% gold content and no stones or non-gold deductions. Values update when you change the reference price; the examples always remain 18K / 750 even if you change the calculator's purity.
Gold API reference · $4,195.60 USD/troy oz · as of Oct 11, 2026, 09:55 AM UTC
| Item weight | Pure gold content | Estimated melt value |
|---|---|---|
| 1 g | 0.750 g | $101.17 |
| 5 g | 3.750 g | $505.84 |
| 10 g | 7.500 g | $1,011.69 |
| 20 g | 15.000 g | $2,023.38 |
A worked 18K calculation
For a 10 g item with no non-gold deductions, multiply 10 by 0.75 to obtain 7.5 g of pure gold. Divide the reference of $4,195.60 USD per troy ounce by 31.1034768, then multiply by 7.5. The estimated metal value is $1,011.69 USD.
If stones and other non-gold parts weigh 2 g, calculate the gold content on the remaining 8 g, not the full 10 g. A hallmark is a starting assumption; an assay may find a different purity.
Metal value, buyer offer and retail price
Metal value estimates the gold content. A buyer's net cash offer is what you receive after any fees and deductions. Retail jewelry prices may include labor, brand premiums, stones and taxes. These figures answer different questions.
The 70% and 90% figures in the calculator are hypothetical arithmetic examples, not typical payouts or a fair-price range. Compare itemized net quotes using the same tested weight and purity. Compare multiple buyer quotes or read the calculation method. Enter your item weight, purity and any non-gold deduction again on the comparison page; inputs are not carried over automatically.
What is 18K gold?
18-karat gold contains 75% pure gold and 25% alloy metals. It has more gold content than 10K or 14K and is commonly used in fine jewelry, luxury watches and wedding jewelry.
18K and 750 hallmarks
Typical marks include “18K,” “18KT” and “750.” The 750 mark represents 750 parts of gold per thousand. White, yellow and rose 18K gold use the same nominal gold percentage even though their alloy metals differ.
How the per-gram value is estimated
Because 18K contains more pure gold, its estimated metal value per gram is higher than 14K at the same market reference.
Before selling 18K jewelry
Fine jewelry may command more than scrap value when its brand, condition, design or stones are desirable. Separate a melt-value estimate from an appraisal of the complete piece.