How to Calculate the Gold Content of ANY Karat Gold Jewelry

While this may seem easy to experienced gold buyers, finders, and sellers, figuring out the percentage of gold contained in any and all pieces of gold (jewelry and otherwise) is vital to figuring out the gold melt value of an item.

Luckily, it's really easy to do, even if you're dealing with vintage pieces of low karat purity or modern and/or repaired pieces that contain less gold than the stamped gold purity implies.

To find the gold content of any karat of gold jewelry, simply divide the karat purity by 24.

Gold Content = Karat / 24

24 karat gold is considered pure gold (which is why you may see 24k gold-plated jewelry, but will not see 24k SOLID gold jewelry... pure gold is too soft).
So in the world of gold purity markings, the karat purity is always based on a total of 24 and goes down in a sliding scale mostly on even numbers (but not always, especially with older pieces).

The alternate to knowing the gold content formula mentioned above, is memorizing the gold contents of each karat purity.  Definitely possible, and many people do memorize the gold contents, but it's still valuable to know how to calculate gold content, especially if you're dealing with an odd karat purity or simply forget one of the numbers.

For reference, here are the common gold karat purities and their corresponding gold content....

10k  -  41.7% pure gold
12k  -  50.0% pure gold
14k  -  58.3% pure gold
18k  -  75.0% pure gold
22k  -  91.67% pure gold

Another time this formula comes in handy is when you suspect a piece of jewelry may contain less gold than the stamped purity.  This is often the case with repaired pieces of gold jewelry... the repair will almost always contain solder and may also contain gold of a lower purity.

In the U.S., it is legal for gold makers to "under-karat" their jewelry by up to 1/2 karat.  This means that gold jewelry makers can use a 13.5 karat gold mixture and still call it 14 karat gold.  Doesn't sound like much until you do the math and realize that's 2% less gold (which can add up substantially on large and heavy gold pieces).
If a piece of gold jewelry has been repaired, it can be up to 1 FULL KARAT LESS in gold purity and still retain the original marking.

This is all very valuable information to know before calculating the gold content and melt value, and especially before buying any piece of gold jewelry as refiners generally pay based on the amount of gold RECOVERED, and not based on the purity markings.

Hope this article helped add some knowledge to your gold scrapping toolkit.

Thanks for reading!

Solid Gold Jewelry - Karat Purity & Gold Content Introduction

With so many different jewelry markings and odd terms being tossed around, at first it may seem daunting to try and figure out the karat purity, gold content, and inherent value... but it doesn't have to be.

Once you understand a few important basics, you'll be well on your way to determining not only if a piece of gold jewelry is real, but equally important tidbits like gold content (purity) and thus, value.

The first term we'll look at is "karat", which is a standard unit used to measure the purity of gold.  It works on a sliding scale up to 24k (pure gold), although you typically won't see jewelry marked less than 10k (older pieces do go lower).  A higher number of karats means the item contains more gold, and lower numbers means less gold.  So if you have a 10k gold pendant that is the identical SIZE of another pendant made of 18k gold, the 10k pendant will not only contain LESS GOLD, it will WEIGH LESS.

In order to find the gold content in a piece of jewelry, you first must know the karat purity.  You can check out the section on Identifying Real Gold Jewelry Markings if you'd like the become familiar with how to spot real gold and tell exactly how much gold is in an item.

Once you know the karat purity of a piece of gold, simply divide that number by 24 and the result equals the percentage of pure gold contained in the item... represented in decimal form.

Example:
Say you have a large men's wedding band, marked "14KT".  14 divided by 24 is 0.58333...  Move the decimal two places to the right and the number is now a percentage.  In this case, the 14 karat gold wedding band is 58.333% PURE GOLD.

The same can be done no matter the karat marking...

• 10k / 24k = 0.41667 = 41.667% PURE GOLD
• 12k / 24k = 0.500 = 50.00% PURE GOLD
• 14k / 24k = 0.58333 = 58.333% PURE GOLD
• 18k / 24k = 0.7500 = 75.00% PURE GOLD
• 22k / 24k = 0.91667 = 91.667% PURE GOLD

So, once you know for sure that the piece in question IS SOLID GOLD, and the PURITY IS KNOWN, the GOLD CONTENT is quickly found per the table above.  Since gold is soft and very malleable, jewelry is rarely made with more than 75% pure gold (18 karat jewelry) but 22k pieces do exist and are out there.  (Keep an eye out for those, they offer one heck of a concentration of wealth in a small package!)

The next step is to figure out the value of the gold in your piece of jewelry.  This is covered in more depth in another section and is the next recommended step to becoming a Gold Jewelry Guru!