What Is a Karat?
A karat (abbreviated K or kt) is the unit used to measure the purity of gold. The system divides gold into 24 parts — so the karat number tells you how many of those 24 parts are pure gold.
24K gold is essentially pure gold (99.9%). 14K gold means 14 out of 24 parts are gold, with the remaining 10 parts made up of alloy metals like copper, silver, zinc, or nickel. These alloys aren't filler — they add durability, change the color, and make the gold practical for everyday jewelry.
Don't confuse karat (gold purity) with carat (gemstone weight, where 1 carat = 0.2 grams). They sound the same but measure completely different things.
Complete Gold Karat Guide
Here's every common karat with its purity, gold content, and typical uses:
| Karat | Purity % | Gold per Gram | $/gram* | Common Uses |
|---|---|---|---|---|
| 24K | 99.9% | 0.999 g | $90.00 | Investment bars, coins, some Asian jewelry |
| 22K | 91.7% | 0.917 g | $82.50 | Indian & Middle Eastern jewelry, coins |
| 18K | 75.0% | 0.750 g | $67.55 | Fine jewelry, luxury watches, European pieces |
| 14K | 58.3% | 0.583 g | $52.50 | Most US jewelry, engagement rings, chains |
| 12K | 50.0% | 0.500 g | $45.00 | Vintage jewelry, some antique pieces |
| 10K | 41.7% | 0.417 g | $37.53 | Affordable jewelry, class rings, earrings |
| 9K | 37.5% | 0.375 g | $33.77 | UK & Australian jewelry standard |
| 8K | 33.3% | 0.333 g | $30.00 | European (especially German) jewelry |
*Approximate values based on $2,800/oz spot price. Use our calculator for live prices.
How Karat Affects Value
The relationship between karat and value is straightforward: higher karat = more gold content = higher melt value per gram. Here's what the same 10-gram chain is worth at different karats:
| Karat | 10g Chain Melt Value | vs. 24K Value |
|---|---|---|
| 24K | $900.00 | 100% |
| 22K | $825.00 | 91.7% |
| 18K | $675.50 | 75.0% |
| 14K | $525.00 | 58.3% |
| 10K | $375.30 | 41.7% |
Based on $2,800/oz ($90.06/g) spot price.
Notice that a 10K chain still holds $375 in gold value — that's significant. The drop from 24K to 10K is roughly 58%, not 100%. Lower karat gold is absolutely worth selling.
How to Identify Gold Karat
There are several ways to determine the karat of your gold, from simple visual checks to professional lab testing:
Look for karat stamps
Check clasps, inner bands, near closures, and on tags. Stamps may read "14K", "585", "14KT", or "14KP" (karat plumb, meaning exact). A magnifying glass helps with small stamps.
Magnet test
Gold is not magnetic. If your piece sticks to a strong magnet, it is not solid gold (though it could be gold-plated over a magnetic base metal). Note: non-magnetic metals like brass can also pass this test, so it only rules out fakes, not confirms authenticity.
Acid test kit
Home acid test kits ($15-30) use nitric acid solutions calibrated for each karat. You scratch the gold on a test stone and apply acid. The reaction (or lack of) indicates the karat. Reasonably accurate but destructive to a small area.
Electronic gold tester
Handheld electronic testers ($50-300) measure conductivity to estimate karat. More convenient than acid but less accurate, especially for plated items.
XRF spectrometry (professional)
X-ray fluorescence analysis is the gold standard. Non-destructive, accurate to 0.1%, and identifies all metals in the alloy. This is what reputable gold buyers (including us) use for every piece.
Common Karat Stamps by Country
Different countries use different marking systems. Here's a reference guide to help you decode what's stamped on your gold:
| Karat | US / Canada | European (Millesimal) | UK / Australia |
|---|---|---|---|
| 24K | 24K, 24KT | 999 | 999 |
| 22K | 22K, 22KT | 916, 917 | 916 |
| 18K | 18K, 18KT | 750 | 750 |
| 14K | 14K, 14KT, 14KP | 585 | 585 |
| 10K | 10K, 10KT | 417 | 417 |
| 9K | N/A | 375 | 375, 9ct |
| 8K | N/A | 333 | 333 |
Note: In the US, 10K is the minimum karat that can be legally sold as “gold.” In the UK and parts of Europe, 9K (375) is the legal minimum. Pieces below these thresholds may still contain some gold but cannot be marketed as gold jewelry.
Calculating Melt Value by Karat
The formula for calculating the melt value of any gold item is simple:
Melt Value = Weight (g) × Karat Purity × Spot Price per Gram
Gold spot price per gram = Spot price per troy ounce ÷ 31.1035
At $2,800/oz: $2,800 ÷ 31.1035 = $90.03/gram
Worked Examples
14K Gold Chain (20g)
20g x 0.583 x $90.03
$1,049.75
18K Wedding Band (6g)
6g x 0.750 x $90.03
$405.14
10K Class Ring (12g)
12g x 0.417 x $90.03
$450.39
22K Bangles (30g)
30g x 0.917 x $90.03
$2,476.12
24K Gold Bar (10g)
10g x 0.999 x $90.03
$899.40
These are melt values. Buyer payouts typically range from 85-95% of melt value for reputable online buyers.
Why Lower Karat Gold Isn't Worthless
A common misconception is that 10K or 14K gold is barely worth selling. The data says otherwise:
10K gold is 41.7% pure — nearly half gold by weight
14K gold is the most common karat in the US, making up roughly 60% of all gold jewelry sold
At current prices, even a small 5g 10K ring holds ~$188 in gold value
Lower karat pieces are often heavier (more durable for daily wear), which offsets the lower purity
Buyers evaluate gold strictly by weight and purity — they don't discount based on karat stigma
The bottom line: if it's real gold, it has real value. A reputable buyer will pay you based on the actual gold content, regardless of the karat.