When shopping for gold jewelry or investment products, you'll encounter karat ratings like 24K, 22K, 18K, and 14K. These numbers tell you how much pure gold is in the item — but the implications for value, durability, color, and pricing are significant. This guide explains everything you need to know about gold purity.
What Does "Karat" Mean?
Karat (abbreviated K or kt) is a unit of measurement for gold purity. Pure gold is defined as 24 karats. The karat number tells you how many parts out of 24 are pure gold. For example, 18K gold is 18/24 = 75% pure gold. The remaining 25% consists of other metals (called "alloy metals") mixed in to alter the gold's properties.
Important: Don't confuse "karat" (gold purity) with "carat" (gemstone weight). They're completely different measurements that happen to sound alike. In the gold world, we're always talking about karats.
The karat system is also expressed as "fineness" — parts per thousand. For example, 24K gold has a fineness of 999.9, and 18K gold has a fineness of 750. You'll often see these numbers stamped on gold bars and fine jewelry.
Gold Purity Breakdown
24K Gold — 99.9% Pure
24K gold is as pure as commercially available gold gets (99.9% or 999.9 fineness). It has a rich, deep yellow color that is unmistakable. All investment-grade gold bars and many bullion coins (Canadian Maple Leaf, Austrian Philharmonic, Australian Kangaroo) are 24K.
However, 24K gold is very soft — you can scratch it with a fingernail. This makes it impractical for everyday jewelry that endures wear and tear. It's also more prone to bending and deformation. In jewelry, 24K gold is primarily used in the Middle East, India, and East Asia, where high purity is culturally preferred and pieces are worn less frequently or more carefully.
Value: Highest gold content per gram. The price per gram equals the full spot price.
22K Gold — 91.7% Pure
22K gold contains 91.7% gold and 8.3% alloy metals. It's slightly harder than 24K but still relatively soft. This is the traditional standard for gold jewelry in India, the Middle East, and parts of Southeast Asia. It's also used for some investment coins, including the American Gold Eagle and South African Krugerrand.
The color is almost as rich as 24K, with only a slight difference visible to trained eyes. 22K is a good balance between purity and durability for jewelry that's worn occasionally rather than daily.
Value: Gold content is 91.7% of the spot price per gram.
18K Gold — 75% Pure
18K gold is the global standard for fine jewelry. With 75% gold and 25% alloy metals, it offers an excellent balance of purity, color, durability, and workability. Most high-end jewelry brands (Cartier, Tiffany, Bulgari) use 18K gold as their standard.
The alloy metals in 18K gold can be chosen to create different colors:
- Yellow gold: Alloyed with silver and copper
- White gold: Alloyed with palladium, nickel, or zinc (often rhodium-plated for extra brightness)
- Rose gold: Alloyed with a higher proportion of copper, giving a warm pinkish hue
18K gold is hard enough for daily wear while still retaining a rich gold color. It's the sweet spot for most jewelry buyers worldwide.
Value: Gold content is 75% of the spot price per gram.
14K Gold — 58.3% Pure
14K gold is the most popular choice for jewelry in the United States, Canada, and much of Europe. At 58.3% pure gold, it's more durable and scratch-resistant than higher-karat options, making it ideal for engagement rings, wedding bands, and everyday jewelry that endures constant wear.
The trade-off is a less intense gold color. 14K yellow gold is noticeably lighter than 18K or 22K, though many people prefer its subtler appearance. 14K white gold is particularly popular, as the higher alloy content makes it naturally whiter and more durable.
Value: Gold content is 58.3% of the spot price per gram.
10K Gold — 41.7% Pure
10K gold is the minimum karat that can legally be sold as "gold" in the United States. At 41.7% pure, it's the most durable and affordable gold alloy, but the color is noticeably pale. It's commonly used for affordable jewelry and gold-accented watches.
Outside the US, 10K gold is less common. Many European countries set 9K (37.5% pure) as the legal minimum for gold jewelry.
Value: Gold content is 41.7% of the spot price per gram.
Karat vs. Value: How to Calculate
To calculate the gold value of any item, you need to know its weight and karat:
Gold value = Weight (grams) × (Karat ÷ 24) × Gold price per gram
For example, a 20-gram 18K gold necklace when gold is $85 per gram:
- Gold value = 20 × (18 ÷ 24) × $85
- Gold value = 20 × 0.75 × $85 = $1,275
This is the "melt value" — the value of the raw gold content alone. A finished jewelry piece will typically be priced higher due to craftsmanship, design, and brand value. Use our live gold price dashboard for current per-gram prices.
Which Karat Should You Choose?
For Investment
Always choose 24K. Investment-grade gold bars and coins should be 99.5% pure or higher. You want maximum gold content per dollar spent. The beginner's guide to buying gold covers the best investment products.
For Fine Jewelry
18K is the global standard for fine jewelry. It offers beautiful color, good durability, and strong resale value. If you're buying from a luxury brand, this is almost certainly what you'll get.
For Everyday Jewelry
14K is ideal for rings, bracelets, and pieces you wear daily. It withstands scratches and bumps better than higher-karat gold and is more affordable.
For Traditional/Cultural Jewelry
22K is preferred in India, the Middle East, and East Asia for wedding jewelry and traditional pieces. Higher purity is considered more auspicious and valuable in these cultures.
How to Identify Gold Karat
Legitimate gold jewelry should be stamped with a karat mark. Look for:
- 24K, 999, or 999.9 — Pure gold
- 22K or 916 — 91.6% pure
- 18K or 750 — 75% pure
- 14K or 585 — 58.5% pure
- 10K or 417 — 41.7% pure
- 9K or 375 — 37.5% pure
If you're buying pre-owned gold or are unsure about a piece's authenticity, a professional jeweler or gold assay office can test the purity using acid tests, X-ray fluorescence (XRF), or fire assay methods.
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