How Much Does a Gold Coin Weigh?

Posted on March 31, 2022

By Paul Vanguard, for BullionMax.com

“How much do gold coins weigh?” You’d think this is a super-simple question to answer. After all, every modern gold bullion coin has its weight stamped right on it.

If I buy a 5 lb. bag of flour at the grocery store, I expect it to weigh 5 lbs.

When I pump a gallon of gas into my truck, boy howdy, I better get a gallon of gas or me and the store owner are going to have words.

But when you get your very first, say, American gold eagle or Krugerrand and you get over the initial excitement, at some point you’re going to wonder whether you have an authentic gold coin or a convincing counterfeit. So you pull out that little digital scale that lives high up in the cabinet and put your 1 oz gold coin on it.

1.197 oz

Huh, that’s weird. You doublecheck the weight, re-zero the scale.

1.197 oz

Well, let’s switch it to grams… You Google the oz-to-grams comparison and learn that one ounce is the equivalent of 28.35 grams. Okay, now your scale says:

33.934 g

Have you been duped? What’s going on? Why does a 1 oz gold coin weigh more than 1 oz?

We’re going to explain it, but first, relax (especially if you ordered from BullionMax!) Let’s not call the police just yet.

How much do gold coins weigh? An insider perspective

Here’s the most important thing to understand: a 1 oz gold coin from a reputable refinery or mint is always going to have an ounce of gold in it.

In the precious metals industry, “weight” doesn’t mean total weight – it means “weight of fine metal.” Some modern gold coins, notably both the entire line of American gold eagles and the Krugerrand, are made from gold alloyed with other metals. In fact, the purity of both eagles and Krugerrands is 0.9167 fine. Now, that sounds like a pretty shoddy gold coin, until you realize that the coin itself weighs more than an ounce – and that extra is silver and copper added to the gold that results in a much more durable, resilient coin.

Historic gold coins were never made of pure gold. It’s just too soft and damage-prone to stand up to daily use as money. (Also, when you’re shopping for historical gold coins, you’ll note that reputable sellers will always tell you the total weight of gold in the coin.)

All right, smart guy, how much to pure gold coins weigh?

Modern “pure” gold coins like the Canadian maple leaf, the buffalo or the kangaroo are minted in at least 0.999 fine gold, aka 24 karat gold, aka pure gold (0.9999 fine is more common nowadays, and sometimes Royal Canadian Mint shows off with a super-special 0.99999 or “five nines” fine gold coin).

Now, maple leafs and kangaroos and buffalos are all very popular coins. But buyers usually know that they have to handle them with special care. They're coins you don't want leaving your safe or display case very often, not ones you hand to children or careless friends. Even if they’re non-collector-grade bullion coins, you have to baby them.

They’re soft. They tend to scuff if you look at them the wrong way, and Canadian maple leafs are notorious for already having wear marks when they arrive fresh from the mint! That’s because just being close to other gold coins, even in a protective sleeve snug in a monster box, that can be enough to mark up the coins.

If you throw one of these on your scale, it will read:

1.197 oz

Well, let’s switch it to grams…

31.103 g

Okay, we know from our earlier Googling that 28.35 grams equals 1 oz. So what the heck?

Gold coins are measured in troy ounces

America got a lot of great things from our former royal overlords back in England: our language. A love of beer. And a medieval system of weights and measures that’s so incredibly byzantine it’s virtually unusable.

See, precious metals are traditionally weighed in troy ounces, which are just a smidge heavier than what we normally think of as an ounce (technically, it’s an avoirdupois ounce). A troy ounce is made of 20 pennyweights, and each pennyweight is 24 grains.

You think I’m making this up, but I’m not.

Troy weights have been in use in England since the 1400s, and in 1527 were made the official weight for measuring gold and silver. Since England was such an economic powerhouse back then, all of Europe started using these English troy ounces to weigh their gold coins, as we do to this day.

And that’s just about all we use troy ounces for! Hunting enthusiasts may have noticed that weights of bullets and broadhead arrow tips are measured in grains rather than ounces or grams – that’s the only other holdover from the archaic weights-and-measures system I’m aware of.

Man, those old English measurements were weird! They included such gems as the poppyseed (1/4 of a barleycorn), the cubit, the furlong (200 meters, horse racing still uses this measure) and leagues (defined as “an hour’s march”!!). My personal favorite is the hogshead, a unit of volume amounting to 3 kilderkins (36 gallons).

Fortunately for our sanity, the British Empire adopted a new measurement system, called Imperial units, in 1824. The U.S. conformed to this new measurement system in 1832, and we’ve used them ever since. (Even after jolly olde England moved on to the metric system…)

So what’s the takeaway?

A one ounce coin weighs more than an ounce… Kind of.

Look, it's no more or less nonsensical than a gold eagle coin having a $50 face value and a $2,200 retail price. It’s a combination of tradition, confusingly-named units of weight and quite frankly a lack of explanation. Yes, it’s confusing! Heck, I just wrote this article and it nearly broke my brain.

Look: there are good reasons why the weight of your gold coin isn’t exactly what you expect. The whole thing can seem misleading, but it’s not deliberately deceptive.

A legitimate 1 oz gold coin will always contain 1 troy ounce of gold, regardless of how much it weighs, or how stupid medieval English goldsmiths were.


Paul Vanguard is a lifelong precious metals enthusiast and a proud member of the BullionMax team.