There are many ways to invest in gold bullion. The most common ways are through the purchase of gold coins and gold bars. Most people are familiar with the sizes of gold coins since they are very similar to the regular currency that is in common circulation. A 1/10 Troy oz coin, for example, is about the size of a U.S. dime, while a 1 Troy oz coin is about the size of an old silver dollar.
Most people, however, are much less familiar with the common sizes of gold bars. When you hear the term "gold bar," the vast majority of people tend to only think of larger size gold bricks, like those seen in a James Bond movie or stored at Ft. Knox. In truth, gold is so rare and valuable that it doesn't take much to be worth a lot. Most of the gold bars available for purchase are a lot smaller, ranging in size from 1 gram up to 1 kilo. This allows the overall purchase, transport and storage of gold bars to be a much simpler and affordable process.
Check out these photos of different sized Perth Mint gold bars, pictured in context with everyday objects.
This should give you a better sense of the general sizes in which gold bars are available:
How Big is a 1 Gram Gold Bar (.032 Troy oz)?
This is the smallest size generally owned for investment purposes. The premium over the “spot price” for these tiny bars is quite high since the manufacturing process is the same as for a larger bar. The benefit of a small bar is that it makes it easy to liquidate small quantities at a time. These are like the “small bills” of the gold world.
The 20 gram is close enough in size and weight to 1 Troy oz that it can easily be mistaken by someone without much experience holding different bars. That’s why it’s important to always check the label to make sure you are certain you know what size bar you are dealing with.
The 1 Troy oz gold bar is the most common size traded around the world. Even countries that use the metric system still produce bars (and coins) in the 1 Troy oz size, since it is so popular. Here in America, we normally convert weights using pounds. 14.58 troy ounces (oz t) in gold is equal to one pound. In the gold business, if someone just says “gold bar,” they are probably referring to the 1 Troy oz size. While we’re on the subject, don’t confuse a Troy ounce (the unit of measure used for precious metals) with the avoirdupois ounce (like your local grocery store or bathroom scale might use). A Troy ounce is “heavier” than an avoirdupois ounce. There are 31.1 grams in a Troy ounce, but only 28.35 grams in a “regular” avoirdupois ounce. This bar is about the same size as a military dog-tag, but a bit thicker.
The 50 gram gold bar is a bit more than 1.5 Troy ounces and feels very solid in the palm of your hand. The price-per-ounce is definitely less than the smaller-size bars, which can make a larger bar like this more economical than buying 50 1-gram bars or 5 10-gram bars.
The 100 gram bar weighs more than 3 Troy oz and is a popular size in the international gold trade. Though the price-per-gram is low, a bar this size limits your options if you ever want to liquidate little-by-little.
A 10 Troy oz bar is a sign of prestige and is an economical way to own and store gold. Due to the value, these are big and valuable enough that storage can require a bit of planning and preparation. The dimensions are similar to about 5 credit cards stacked on top of each other.
How Big is a 1 Kilo Gold Bar (32.15 Troy oz | 2.2 lbs)?
The largest commonly available gold bar for individual investors is the 1 kilo bar. While still far shy of the 400 Troy oz “good delivery bar” that is traded on the Commodities Exchange, the kilo bar is quite hefty and feels amazing in your hand. Though it’s essentially the same size as an iPhone 6, it weighs substantially more since gold is so dense.