How to Calculate the Price per Gram of Gold Scrap
How precious is gold? Well, people have been recycling it in all the millennia they've been using it—which should give you your answer. If you're going through your old knickknacks with the idea of selling the gold pieces to someone—like refiners, or maybe pawn shops—then you'll want to get a ballpark figure of their value so you're not ripped off.
Here you will learn how to use simple math to calculate the price per gram of gold scrap. Your tools are minimal—a calculator, a gram scale, and of course you need to know the karat weight (10K, 14K, 18K, or 24) of the gold items, which may require a magnifying glass. So dig up your supplies and let's get started.
Three important notes before we start:
- You'll only be estimating how much cash you should be offered. Remember that most dealers make their profits by offering a fixed percentage less than the current market value.
- The value of gold, which is traded in all time zones 24 hours a day, changes constantly, with its price set in London twice daily. This means if you decide to sell the gold one day and actually conduct the transaction on another day, its value will have changed.
- This method won't work for gold-plated items.
Step 1: Find the Current Price of Gold
The first step is simply to write down the dollar amount of the current price of gold. This can be found online. Websites such as Goldprice.org, Kitco.com, and Monex.com track the metal markets, and so do some unexpected sites. For example, when I was selling my handcrafted jewelry, I would check gold and silver markets right at the store from which I bought my precious metals.
So if today the price of gold happens to be $1,000 per troy ounce, then write down $1,000. (On the date of this March 2015 revision, the number is higher—over $1,300. But we'll use $1,000 because it's an easy round number.)
Step 2: Find the Price of Gold Per Gram
Divide $1,000 by 31 grams. (Remember, that $1,000 figure is in this example only - when you do it, use the real gold price). The result is the price of gold per gram - in this example, approximately $32.26.
Why 31 grams? The price of gold is conventionally measured in troy ounces. One troy ounce is 31.10348 grams. Here, to make things easy, I rounded this number to 31 grams. If you are not too math-challenged, then feel free to use all the decimal places.
Step 3: Sort Your Scrap into Piles of Fineness
Now you're ready to sort your gold into piles by its purity, that is, by how much actual precious metal versus base metal is in the scrap. You will calculate the value of each pile separately.
Use a magnifying glass if necessary to determine the fineness of the gold, then sort it into piles by fineness (10K, 14K, 18K, or 24K, where K means karat).
Note: Gold-plated scrap cannot be weighed this way and should be excluded from this calculation.
Step 4: Weigh the Scrap Gold
Weigh each pile using a gram scale. Write down how much it weighs in grams.
Alternatively, you can use an accurate scale that uses standard avoirdupois ounces or troy ounces as a unit and then manually converts to grams. If you do this, then note that for every avoirdupois ounce of scrap gold you have, you have approximately 28.35 grams of gold. (So if you had 3.2 ounces of gold, you'd have 3.2 times 28.35 or 90.72 grams. If your scale measures in troy ounces, you'd have 3.2 times 31.10348, which would be 99.53 grams. This example is just for use in explaining this step—don't use it in the calculations below.)
Step 5: Calculate the Gold Price According to the Amount of Pure Gold in the Alloy
Do the simple calculation below for each pile. Multiply as described using the number from Step 2 (the price of gold per gram):
Chart: Operation to Perform - By Karat Weight
10 karat (10K) gold...
multiply the price by .4167.
14 karat (14K) gold...
multiply the price of gold per gram by .5833.
18 karat (18k) gold...
multiply the price of gold per gram by .75.
24 karat (24k) gold...
multiply the price of gold per gram by 1 (which will yield the same result you began with).
gold of another karat weight...
multiply the price of gold per gram by the karat weight divided by 24.
The result you end up with is the scrap gold price per gram of that karat weight of gold.
Step 6: Calculate the Current Market Price of Gold Scrap
Now the final step: Multiply the number you figured from Step 5 times the weight of gold in grams from Step 4.
Example: If you had 50 grams of 10 karat gold, and if the gold price per gram of 10K gold was $12, then you would have scrap gold with an estimated $600 current market value.
Need to know the value of scrap gold jewelry in pennyweight?
Check out my article with step-by-step instructions.
If you have any trouble, please leave a comment and tell me where you're stuck, and I'll try to help you. Good luck!
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
© 2009 Chris Telden