What is 18ct gold and what is the current 18ct gold price per gram?
18ct Gold is an alloy of gold and other base metals. Most often, the base metal content is either copper or zinc.
18ct hallmarked gold contains at least 75% gold. This means that base metal content would be the remaining 25%.
18ct White Gold will either contain zinc or silver as opposed to copper to the 18ct gold alloy.
The value of any gold is based on it’s gold content. As such, the value of 18ct yellow gold is exactly the same as 18ct white gold or 18ct rose gold.
Calculate the 18ct gold price per gram
Get the LBMA gold price per ounce

LBMA Gold Fixing for Friday 25 October
The LBMA Gold price is published on the London Bullion Market Association website.
The prices are published per troy ounce and show the value of Pure Gold.
Convert to price per gram
Let’s assume the LBMA Gold Price is £832.561. This means that the Pure Gold Price per gram is £26.76 because there are 31.10347 grams in every troy ounce.
832.561 / 31.10347 = £26.76
Calculate 18ct Gold Price Per Gram
Because 18ct gold is 75% pure, then this means that the 18ct Gold Price Per gram is 75% of the pure gold price per gram.
So how do we work that out?
£26.76 * 75% = £20.07