Guide To Measuring Your Gold – Grams In An Ounce Of Gold

If you are interested in collecting and investing in gold (and other precious metals), you need to know how its value is assessed. While many factors contribute to it, such as purity, one of the most important things is its weight. 

Gold is unique in that it is measured by troy ounce, which is different from the standard imperial ounce. Read on to learn why this precious metal uses a different standard of measurement and how many grams make up a standard ounce of gold.

Basics Of Measurements

What Is A Gram?

Part of the metric system introduced in the 1700s, gram (g) measures mass or weight. In most countries in the world, it is the standard unit of measurement for solid (i.e., non-liquid) objects. It is widely used in labeling ingredients, nutrition labels, food, and other products.

With the wider adoption of the metric system, it is becoming more common to measure gold’s weight in grams. That said, gold is special in that it uses its own system of measurement: the troy system.

What Is A Troy Ounce?

A troy ounce (oz t) is a unit of measurement solely used for precious metals such as platinum, silver, and gold, no matter the form – this includes gold coins and gold bullions such as Krugerrand, Canadian Maple Leaf, and Britannia. A troy ounce weighs roughly 31.10348 grams.

The troy ounce is part of a system that has several other units of measurement:

  • Grain: 64.79891 milligrams
  • Pennyweight (dwt): 24 grains
  • Troy ounce (oz t): 20 pennyweights
  • Troy pound (lb t): 12 troy ounces

Standard Ounces vs Troy Ounces

Part of the imperial system, the regular ounce (also known as the avoirdupois ounce) is a unit of measurement for mass, weight, and volume. It can be used for both solid objects and liquids. A standard ounce weighs 28.35 grams, roughly 2.75 grams (10%) less than the troy ounce.

Why You Should Know Your Gold’s Weight

It’s important to know the different ways to measure gold because sellers and buyers may use different standards of measurements. Some shady sellers may even try to trick customers and make their listings seem cheaper by posting the weight in standard ounces and not in troy ounces – basically shortchanging them as regular ounces weigh less.

How Many Grams Are In An Ounce Of Gold?

Using the troy system, there are roughly 31.1 grams in an ounce of gold.

Converting Grams To Troy Ounce

If you know how to weigh your gold in grams, you can convert it to a troy ounce. One gram is equal to roughly 0.03215 troy ounces. So, if your gold weighs 150 grams, it would be 4.8225 troy ounces.

How To Measure Gold Purity

While it’s important to know its weight, it is equally important to know how pure your gold is – this is the second major determinant of its value. 

Gold purity (as well as the purity of other precious metals) is measured in karats (K). The higher the karat, the purer the metal. This tells you how much gold there is in your gold coin or other asset. “Pure” gold is not mixed with any other metal.

Karat is the ratio of gold to other precious metals and alloys. One karat represents 1/24 of the mixture. So, for example, if a gold coin is 10 parts gold and 14 parts alloy, its purity is rated 10K.

Below are some facts on karatage:

  • Karats can range from 0-24K, but most gold is sold at 9K, 10K, 12K, 14K, 18K, 22k, and 24K.
  • Gold’s highest purity is 24K. At this karatage, it is pure gold – there are no other metals or alloys mixed in.

If you want to compute how pure your gold is, divide its number of karats by 24 to get a percentage:

(Karats [K] / 24) X 100 = Purity (%)

Ex: 14K = 58.3%

Take note that “karat” is technically different from “carat”, which measures the size of precious gems such as diamonds. That said, it’s still widely acceptable to use “carat” when referring to the purity of gold. 

How To Calculate Your Gold’s Value Based On Weight

When buying or selling gold, the first thing you should do is calculate its weight – this is one of the major determinants of its price. Read through for a guide on how to calculate your gold’s weight and its value.

Weigh Your Gold

Use a scale to measure your gold’s weight. Most standard scales measure in grams, but you can buy specialized gold weighing scales to get it directly in troy ounce. 

If you want to convert grams to troy ounce, use this formula:


Grams (g) X 0.03215 = troy ounce (oz t)

Ex: 150 g = 4.8225 oz t

If you want to convert troy ounce to grams, use this formula:

Troy ounces (oz t) X 31.10348 = grams (g)

Ex. 150 oz t = 4665.522 g

Get Your Gold’s Value

You can estimate the price of gold by taking its weight in grams or troy ounce and purity into consideration. That said, keep in mind that the value of gold changes over time. 

Do your own research on the current prices of gold by weight and karat. You can check prices online – plenty of websites even have a live feed of the value of gold bullion and other precious metals.

Once you know the current value of gold by karat and weight, simply multiply your gold’s weight by the market price:

Weight (g or oz t) X market price ($/g or oz t) = Value of your gold ($)

Let’s say you have a 24K gold bullion weighing 1.5 oz t and the current market price is $1500 per oz t. Using the formula above, you can estimate that your gold is worth $2250.


Knowledge is power, especially when it comes to making investment decisions about gold. If you want to get your money’s worth and find the best deals, you need to know how to calculate gold’s value and the various factors that affect its price. 

Aside from purity, one of the biggest factors is weight. You can measure gold in grams, but it is typically measured by its own special unit of measurement called the troy ounce. A troy ounce is different from a standard ounce and is equal to roughly 31.1 g.

If you still want to know more about gold’s weight and purity, refer to the frequently asked questions below. Also checkout this post or purchasing Credit Suisse gold bars.

Frequently Asked Questions

How pure is an ounce of gold?

Weight and purity are two different things. Gold’s weight is typically measured in grams (g) or troy ounces (oz t), while purity is measured in karat (K). Gold is typically sold at 9-24K, ranging from 37.5-100% purity.

What does “fine gold” mean?

“Fine gold” means that gold is almost pure. This is represented by a three-digit number. For example, gold with 99.9% purity would be listed as “.999” or “999”.

“Fine gold” can also refer to small gold flakes or dust. 

What is the smallest unit of gold?

If a piece of gold weighs less than a troy ounce (oz t), it can be weighed in grams (g), which is a much smaller unit of measurement. One gram of gold is equal to roughly 0.03215 oz t.

Social Sharing

Peter Grantham

Peter has been an avid investor in for all his life. Over that time he has accumulated a wealth of knowledge and experience including stocks, bonds, real estate, retirement, precious metals, cryptocurrencies and business investments. You can get in touch at my email: As the owner of this site "My Gold Silver Bitcoin", he aims to bring his knowledge and experience to new investors and seasoned veterans. My mailing address is: 41847 Moen Grove, Greenton, Arkansas, 80976

The owners of this website may be paid to recommend Goldco. The content on this website, including any positive reviews of Goldco and other reviews, may not be neutral or independent.

Live Precious Metals Prices

Latest Posts

Related Articles

Idaho Retirement: The Best Places to Live in the Gem State
Ahh, Idaho … the 'Gem State.' There is nothing far off the beaten path about Idaho’s popularity as ...
Read More
Investing for Retirement Income: Strategies to Maximize Your Savings
The idea of retirement income likely evokes both excitement and anxiety – excited about a future of leisure ...
Read More
Retirement in Colorado: The Best Places to Retire in the Rocky Mountains
For many retirees, the ideal retirement involves the freedom to explore a life of leisure in a locale ...
Read More