Remember that

Gold is measured in TROY ounces, not ounces – Both are not the same.

An ounce weighs 28.35 grams

A TROY ounce weighs 31.103 grams

Therefore, to get the price of gold in grams we do the following:

• Check the daily spot price of gold ie London Metal Exchange Rate. This will show the prevailing price per troy ounce.
• Divide todays gold price in dollars per ounce by 31.103 to get todays gold price per gram.

For example, if the price today was USD$ 1,400 then todays price per gram would be USD$ 1,400 / 31.103 = USD$ 45.02 per gram

If you are actually purchasing or selling gold then you would simply multiply the per gram price with the number of grams of gold you have.  Bear in mind that we are referring to pure gold, referred to as either 24 karat or .999 pure.

If you have lower purity gold you will need to price your gold by the decimal value of the purity:

24k = .999

22k = .917

20k = .833

18k = .750

16k = .667

14k = .583

12k = .500

10k = .417

So, one more example, Say you have an 14k gold necklace that weighs 3.5 grams. With the gold spot price at USD$1,400 per troy ounce.

We convert this to grams by USD$1,400 / 31.103  = USD$ 45.02 per gram.

We get the full weight by price per gram x weight in grammes

USD$45.02 x 3.5 = USD$ 157.57

We then take into account the purity

Price of gold necklace in grammes x purity

USD$ 157.57 x .583 = USD$ 91.87

So the spot price of the gold necklace is USD$ 91.87.

If you are selling this necklace the next step is to get as close to this price as possible as the gold or jewellry shop will want to make a profit too. So expect realistically to get around 75% of that price.  If you are buying it same principle expect to pay around 25% more.  Really, there isn’t much difference in the way car dealers work and jewellers. They will be happy to do business with you but know what the markup is. That way you can shop around for best price.