18K gold contains 75% gold, 14K contains 58.33%, and 10K contains 41.67%. At the same weight and spot price, 18K has the highest melt value and 10K has the lowest.
Purity drives melt value
Karat is a 24-part purity scale. Divide the karat number by 24 to estimate the gold fraction.
That means 10K is 10/24 gold, 14K is 14/24 gold, and 18K is 18/24 gold.
Why lower karat gold exists
Lower karat jewelry can be harder and less expensive because it contains more alloy metal.
Higher karat jewelry has richer gold content but can scratch or bend more easily depending on the alloy and design.
How to compare offers
Weigh each karat group separately and calculate melt value for each group.
Do not average mixed karats unless the lot has been tested and weighed carefully.
Common questions
Is 18K always worth more than 14K?
At the same weight, yes, 18K has more gold content. A finished 14K designer piece can still sell for more than an 18K scrap item if brand or craftsmanship matters.
What is 14K gold purity?
14K gold is 14 parts gold out of 24, or about 58.33% gold by weight.