KaratCalc

Calculate the metal value of gold based on current spot prices

Live Spot Price
Real-time gold market price

1 troy oz = 31.10 g

24K
Pure Gold
$0.00
100.00% pure
22K
High Purity
$0.00
91.67% pure
18K
Fine Jewelry
$0.00
75.00% pure
14K
Standard Jewelry
$0.00
58.33% pure
10K
Minimum Karat
$0.00
41.67% pure
9K
Budget Jewelry
$0.00
37.50% pure

Values are calculated based on metal content only and do not include premiums, craftsmanship, or numismatic value

What is Karat?

Karat (often spelled "carat" in some contexts) is a unit of purity used to measure the fineness of gold. It indicates the fraction of pure gold in a gold alloy, with 24 karats representing 100% pure gold. The higher the karat number, the purer the gold content, and consequently, the higher the value per unit of weight.

Gold in its purest form (24K) is too soft for most jewelry applications, so it is often mixed with other metals like copper, silver, or zinc to create stronger alloys. These alloys maintain gold's beauty while improving durability for everyday wear.

Common Karat Ratings

24K Gold

99.9% Pure

Pure gold, ideal for investment and collectibles. Too soft for daily jewelry wear.

22K Gold

91.67% Pure

High purity gold, commonly used in fine jewelry and traditional pieces, especially in Asian jewelry.

18K Gold

75% Pure

Fine jewelry grade, offering a balance between gold content and durability. Popular choice for engagement rings and fine watches.

14K Gold

58.33% Pure

Standard jewelry grade, highly durable and long-lasting. The most popular choice for everyday jewelry in the United States.

10K Gold

41.67% Pure

Minimum karat for legal "gold" marking in the US. Very durable but lower gold content.

9K Gold

37.5% Pure

Budget jewelry grade with lower gold content. Commonly used in fashion jewelry and affordable pieces.

How Karat is Calculated in Gold Value

The value of gold is determined by multiplying the spot price of gold (per troy ounce) by the purity fraction and the weight of the item. This tool calculates the metal value using the following formula:

Gold Value = Spot Price × Weight × Purity Factor

Spot Price: The current market price of pure (24K) gold per troy ounce.

Weight: The total weight of the gold item in troy ounces or grams.

Purity Factor: A decimal representing the karat purity. For example, 18K gold has a purity factor of 0.75 (because 18 ÷ 24 = 0.75).

For example, if gold costs $2,000 per troy ounce and you have 1 troy ounce of 18K gold, the metal value would be: $2,000 × 1 × 0.75 = $1,500.

Important Notes

  • The values calculated here represent the metal content only and do not include premiums, dealer markups, or craftsmanship costs.
  • Gold purity is often marked as "hallmarks" on jewelry items (e.g., 585 for 14K, 750 for 18K, 925 for sterling silver).
  • Spot prices vary throughout the day based on global market conditions.
  • Different countries may have different minimum karat standards for labeling something as gold.