How Many Grams Are In An Ounce Of Gold?
One ounce of gold weighs 31.103 grams, as gold is measured in troy ounces rather than standard ounces. Gold and other precious metals are measured in troy ounces, which are a bit heavier than the ounces we use for everyday items. This means an ounce of gold weighs more in grams than an ounce of sugar or water.
Key Takeaways
- One troy ounce of gold = 31.103 grams. In the gold world, “one ounce” always means a troy ounce, which is about 10% heavier than a standard ounce.
- Gold uses the troy weight system: Precious metals are weighed in troy ounces (31.103g), not the usual avoirdupois ounces (28.35g). This historic system ensures consistency in gold pricing worldwide.
- 1 ounce of gold is very valuable: At current rates, 1 ounce of gold is worth £3,088.06 – but the gold price today can change rapidly. Always check our live gold price page for the latest value.
- Useful for selling gold: Knowing grams-to-ounces helps if you plan to sell gold jewellery, coins, or bullion. Buyers quote prices in gold ounce (UK) terms or per gram, so understanding the conversion ensures you get a fair deal.
How Many Grams In An Ounce Of Gold?
There are 31.103 grams in one ounce of gold. Importantly, this refers to a troy ounce of gold, the standard unit used for precious metals. A troy ounce is slightly heavier than the ordinary ounce (called an avoirdupois ounce) that you might use for measuring food. Specifically, while a standard ounce is 28.35 grams, a troy ounce is 31.1034768 grams . That’s about 10% more weight. In practice, when someone talks about an ounce of gold, they almost always mean a troy ounce .
The troy ounce has been the universal measure for gold for centuries. It originated from the medieval markets in Troyes, France, and it’s still used today to avoid confusion in international gold trading. (If you’re curious about the history and details, see what is a troy ounce of gold? for a deeper dive.) The key point is: gold ounces = troy ounces. So if you have a gold coin labeled “1 oz”, it contains 31.103 grams of pure gold.
Having this conversion in mind is useful. For example, if you know gold’s price per gram, you can multiply by 31.103 to get the price per ounce (and vice versa). It’s also handy for comparing the weight of gold coins and bars. Many popular gold coins (like the Krugerrand or Britannia) weigh one troy ounce (31.103g) of gold content, whereas a standard UK ounce (avoirdupois) would only be 28.35g – but remember, we don’t use standard ounces for gold.
(One-troy-ounce gold bars from various refiners (Johnson Matthey, Heraeus, Umicore, Metalor, Perth Mint). Each bar contains 31.103 grams of 99.99% pure gold (the standard weight of one troy ounce). Despite their small size, these 1 oz gold pieces carry significant value)
Live Gold Price Per Gram
Gold price last updated:
Wednesday, 21 October 2026, 12:32.
The LBMA (London Bullion Market Association) spot price changes daily.
The prices displayed are based on the global market rate for pure 24ct gold, known as the spot price. Like all gold dealers, GoldSell pays a percentage of this rate to account for assaying, refining, secure logistics, market volatility, and handling costs. We consistently offer among the highest payout rates in the UK, with the exact percentage increasing based on the weight and purity of the gold you sell.
How Much Is An Ounce of Gold?
The live gold price of 1 ounce of gold is £3,088.06 in the UK today. This value changes constantly with the market – the gold price today could be different tomorrow. Gold trades on global markets 24/7, and prices fluctuate based on supply, demand, and economic factors. That’s why it’s best to check the live gold price for the most accurate valuation.
For context, gold prices are usually quoted per troy ounce in USD, GBP, or other currencies. In the UK, you’ll often see the gold ounce price UK quoted in pounds sterling. If we break it down to grams, since one troy ounce is 31.103g, you can divide the ounce price by 31.103 to get the gold gram cost. For example, if gold is £3,088.06 per ounce, that’s £99.28 per gram. Keep in mind the market moves constantly, so use our live gold price page to see real-time prices per gram for different purities (carats).
When selling gold items, the weight and purity of your gold directly determine its value. Jewellers and gold buyers use troy ounces and grams to calculate payouts. For instance, if you sell gold jewellery, the buyer might quote a price per gram for 9ct, 18ct, 22ct, etc., based on the live market price. Similarly, if you have broken or mixed-karat gold, you’d be looking at scrap value, which is priced per gram of fine gold – see our Sell Scrap Gold page for details.
For investors with gold coins or bars, the one-ounce format is very common. A 1 oz gold coin (24k pure) or a 1 oz bullion bar will closely follow the market price (minus a small premium or dealer fee). At £3,088.06/oz, a one-ounce gold coin would fetch around that price. If you plan to sell gold coins or sell gold bullion, knowing that each “ounce” contains 31.103 grams helps you estimate their value. Even fractional gold coins are often measured in troy ounces (for example, a half-ounce coin has ~15.55g of gold).
Don’t forget historical coins like sovereigns: a British gold Sovereign contains about 7.32 grams of gold, which is 0.2354 troy ounces. So it takes roughly 4.25 sovereigns to make one full troy ounce of gold. If you have a bunch of sovereigns to sell, understanding the ounce/grams math lets you cross-check the total weight. (Visit our sell gold sovereign coins to receive the best price for your gold Sovereign coins.)
Bottom line: An ounce of gold is a significant chunk of value in a small package. Always use troy ounces for precious metals. Double-check the live price (per ounce or per gram) when calculating how much your gold is worth. This way, whether you’re buying, selling, or just curious, you have the right numbers in mind.
Frequently Asked Questions
How many grams in an ounce of gold?
One troy ounce of gold is equal to 31.103 grams. This is the standard measurement for gold weight. Note that this is different from a regular ounce (28.35g). When dealing with gold, “1 ounce” always means 31.103 grams of pure gold in the troy system.
What is the live gold price per troy ounce?
As of 21 Oct 2026, the troy ounce of gold price is £3,088.06 based on the live gold price.
How many grams of gold in a troy ounce?
Exactly 31.1034768 grams of gold make up one troy ounce. In everyday terms, we usually round it to 31.103 grams. This precise unit (established by the Royal Mint and others) is used worldwide for gold, ensuring everyone means the same thing by “1 oz of gold.”
What is a troy ounce?
A troy ounce is a unit of weight used for precious metals like gold, silver, and platinum. It equals about 31.103 grams, making it heavier than the 28.35g ounces used for groceries. The troy ounce has been the standard for gold bullion and coin weights for centuries, originating from a medieval French market system. In short, it's the special ounce just for metals.
What does an ounce of gold look like?
An ounce of gold is surprisingly small but dense. It can be a coin roughly the size of a large coin (around 32 mm in diameter) or a small bar. For example, a 1 oz gold coin (like a Krugerrand or Britannia) fits in the palm of your hand and weighs 31.1 grams. A 1 oz gold bar might be about the size of a matchbox, but it’s heavy because gold is dense.
How many ounces in a 100 gram gold bar?
A 100g gold bar contains approximately 3.215 troy ounces of gold. We get this by dividing 100 by 31.103. In other words, 100 grams is just over 3 troy ounces. Mints often produce bars in common sizes like 1 oz, 50g, 100g, etc., so 100g is a little more than three 1 oz bars worth of gold.
How many gold ounces in a pound?
Precious metals are weighed differently than everyday items. In the troy system, there are 12 troy ounces in a troy pound. However, the standard avoirdupois pound (the one with 16 ounces that we use for things like food) would equal about 14.58 troy ounces of gold. In simpler terms: a “pound of gold” is usually meant to be a troy pound (12 troy oz), but if you used the normal pound, that same weight would contain more than 12 troy ounces (approximately 14.58).
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