Gold is always measured in troy ounces, not the standard ounces used for everyday items. One troy ounce equals 31.1 grams, and every gold bar, coin, and round you buy is priced and weighted using that standard. Whether you are shopping for a 1 gram bar or a 1 oz American Gold Eagle, knowing the weight specs before you buy helps you verify what you are getting and compare products accurately.
A troy ounce weighs 31.1 grams. A standard avoirdupois ounce, the kind used on a kitchen scale or a postal label, weighs 28.35 grams. That gap of nearly 3 grams matters when you are buying gold. If you weigh a gold coin on a standard scale and compare it to the listed troy ounce weight, the numbers will not match, and that does not mean anything is wrong. Precious metals have used the troy system for centuries, and every reputable dealer prices and labels gold products in troy ounces.
This is one of the most common points of confusion for new buyers. A coin described as containing 1 troy ounce of gold does not always weigh exactly 1 troy ounce on a scale. The American Gold Eagle, for example, is a 22-karat coin made from a gold-silver-copper alloy. It contains exactly 1 troy ounce of gold, but its total weight is 1.0909 troy ounces because of the added alloy metals. The Canadian Gold Maple Leaf, by contrast, is 24-karat .9999 fine gold and weighs exactly 1 troy ounce total. The gold content is what you are paying for in both cases. The total weight just depends on whether the coin includes alloy metals.
Gram bars are the entry point for gold buyers who want to start small or add to a position gradually. They carry higher premiums per ounce than larger bars, but they offer flexibility and a lower upfront cost.
Common gram bar sizes and their troy ounce equivalents:
1 gram = 0.032 troy oz
5 grams = 0.161 troy oz
10 grams = 0.321 troy oz
20 grams = 0.643 troy oz
50 grams = 1.608 troy oz
100 grams = 3.215 troy oz
Once you move into troy ounce territory, premiums drop and liquidity improves. The 1 oz gold bar is the most widely traded retail size in the world, and it is what most buyers default to when building a position in gold. Larger bars are better suited for buyers who prioritize cost efficiency over flexibility.
1/10 oz = 3.11 grams
1/4 oz = 7.78 grams
1/2 oz = 15.55 grams
1 oz = 31.1 grams
10 oz = 311 grams
1 kilo = 1,000 grams/32.15 troy oz
The 400 troy ounce Good Delivery bar is the standard used by central banks and institutional bullion traders. It weighs approximately 27.4 pounds and is not sold to individual retail buyers. You will see it referenced in news coverage of gold reserves and futures markets, but it has no practical relevance for most buyers. The retail market starts and ends well below that size.
The American Gold Eagle is the official gold bullion coin of the United States, struck by the U.S. Mint in 22-karat gold. Because it contains a small amount of silver and copper alloy for durability, each coin weighs slightly more than its stated gold content.
1/4 oz Gold Eagle: contains 1/4 oz gold, total weight 8.483 grams
1/2 oz Gold Eagle: contains 1/2 oz gold, total weight 16.966 grams
1 oz Gold Eagle: contains 1 oz gold, total weight 33.93 grams (1.0909 troy oz)
The Gold Buffalo is the U.S. Mint's 24-karat coin, struck in .9999 fine gold. It is only available in 1 oz, and because it contains no alloy, it weighs exactly 31.1 grams. Buyers who want the highest purity available from the U.S. Mint choose the Buffalo.
The Royal Canadian Mint's Gold Maple Leaf is one of the purest gold coins in the world at .9999 fine. Because it contains no alloy, each coin's total weight matches its gold content exactly.
1/10 oz Maple Leaf: 3.11 grams
1/4 oz Maple Leaf: 7.78 grams
1/2 oz Maple Leaf: 15.55 grams
1 oz Maple Leaf: 31.1 grams
The Krugerrand is the world's first modern gold bullion coin, introduced in 1967. Like the Gold Eagle, it is struck in 22-karat gold with a copper alloy, so its total weight exceeds its gold content.
1/10 oz Krugerrand: total weight 3.393 grams
1/4 oz Krugerrand: total weight 8.482 grams
1/2 oz Krugerrand: total weight 16.965 grams
1 oz Krugerrand: contains 1 oz gold, total weight 33.93 grams (1.0909 troy oz)
Gold rounds are privately minted and carry no face value or government guarantee. They are produced in .999 or .9999 fine gold, which means their total weight matches their gold content, just like the Maple Leaf or Gold Buffalo. A 1 oz gold round weighs 31.1 grams. Rounds are available in the same fractional sizes as coins and are often the lowest-premium option for buyers focused strictly on gold content.
1/10 oz: 3.11 grams
1/4 oz: 7.78 grams
1/2 oz: 15.55 grams
1 oz: 31.1 grams
Because rounds are .999 or .9999 fine with no alloy, these weights are consistent across virtually all privately minted products.
Gold weight specs are not just trivia. They tell you what you are actually getting, help you verify a product against its listing, and give you a baseline for comparing bars, coins, and rounds side by side. A 1 oz Gold Eagle and a 1 oz gold bar both contain the same amount of gold, but they weigh different amounts on a scale for reasons that have everything to do with how they are made. Once you understand that, the numbers start working for you. Browse Monument Metals' full selection of gold bars, gold coins, and gold rounds to find the right product for your budget and strategy.
A 1 troy ounce gold bar weighs 31.1 grams. This is not the same as a standard ounce, which weighs 28.35 grams. All gold bars are measured in troy ounces, so when a bar is listed as 1 oz, that refers to the troy ounce standard used throughout the precious metals industry.
The American Gold Eagle is struck in 22-karat gold, which means it contains a small amount of silver and copper alloy in addition to its gold content. A 1 oz Gold Eagle contains exactly 1 troy ounce of gold but has a total weight of 33.93 grams because of that alloy. The extra weight is not extra gold, but it does make the coin more durable than a pure 24-karat coin.
A kilo gold bar weighs exactly 1,000 grams, which equals 32.15 troy ounces. It is one of the most popular sizes among high-volume buyers because it carries a lower premium per ounce than smaller bars while remaining more manageable than the 400 oz Good Delivery bars used in institutional trading.
A 1 oz gold round and a 1 oz Gold Maple Leaf or Gold Buffalo both weigh 31.1 grams because all three are .999 or .9999 fine gold with no alloy. A 1 oz American Gold Eagle or Krugerrand, however, weighs 33.93 grams because those coins are 22-karat and contain alloy metals. The gold content is 1 troy ounce in all cases, but the total physical weight differs based on purity and composition.
A 1 oz gold bar weighs about 0.069 pounds, which is just over 1 ounce on a standard scale. A kilo bar weighs approximately 2.2 pounds. The 400 oz Good Delivery bar used by central banks weighs about 27.4 pounds, though that size is not available to retail buyers.