Gold value formula
Value = weight in grams × purity ÷ 31.1035 × spot price per troy ounce
Gold purity chart
| Karat | Gold content | Common stamp | Typical use |
|---|
| 24K | 99.9% | 999 | Bullion bars and coins |
| 22K | 91.7% | 916 | Gold coins (like the American Eagle), South Asian jewelry |
| 18K | 75% | 750 | Fine jewelry |
| 14K | 58.3% | 585 | Most US jewelry |
| 10K | 41.7% | 417 | Affordable jewelry, class rings |
Selling gold: tips
- Separate pieces by karat and weigh each group; buyers should do the same.
- Get quotes from several buyers and ask what percentage of spot they pay.
- Gemstones and non-gold parts are usually not counted, or are removed first.
- Designer or antique pieces can be worth more than melt value. Get them appraised before selling for scrap.
Need to convert grams and ounces? Use the unit converter. Comparing the price with years past? Try the inflation calculator.
Last reviewed October 2026.
Frequently asked questions
How do I calculate the value of my gold?
Multiply the weight by the gold purity to get the pure gold content, convert it to troy ounces, and multiply by the current spot price per troy ounce. For 10 grams of 14K gold at a $4,000 spot price: 10 × 0.583 ÷ 31.1035 × $4,000 ≈ $750.
Why doesn't the calculator show a live gold price?
Gold prices change all day and free price feeds are unreliable, so you enter today's spot price yourself. You can find it on financial news sites or any bullion dealer's website. This also lets you see the value at any price.
What is a troy ounce?
Precious metals are priced in troy ounces. One troy ounce is 31.1035 grams, about 10% heavier than a regular (avoirdupois) ounce of 28.35 grams. Jewelers also use pennyweight (dwt): 20 dwt make one troy ounce.
How much will a jeweler or pawn shop pay?
Buyers pay less than the melt value to cover refining and profit. Gold buyers and refiners often pay 70% to 90% of melt value, and pawn shops may pay less. Use the "payout" box to see what a given percentage would give you.
What do the karat numbers mean?
Karats measure purity out of 24. 24K is pure gold (99.9%), 18K is 75% gold, 14K is 58.3% and 10K is 41.7%. In Europe, purity is often stamped as a number: 750 for 18K, 585 for 14K and 417 for 10K.