What gold bars cost and weigh at each size: 1 gram, 1 oz, 10 oz, 1 kilo and the 400 oz London Good Delivery bar, how to calculate the price, and what premiums add.
Short answer: a gold bar costs its weight in troy ounces × the gold spot price + a dealer premium. A 1 oz bar weighs 31.1 g, a 1 kilogram bar weighs 1,000 g (32.15 troy oz), and a 400 oz London Good Delivery bar weighs about 12.4 kg (27.4 lb). At an illustrative $4,000 per ounce, those are roughly $4,000, $128,600 and $1.6 million respectively, before premium. Prices move constantly, so use a live spot price.
The table uses an illustrative gold price of $4,000 per troy ounce, so you can see how the sizes scale. It is not a live quote, and it excludes premium.
| Bar | Troy ounces | Grams | Everyday weight | Metal value at $4,000/oz |
|---|---|---|---|---|
| 1 gram | 0.0322 | 1 | 0.035 oz | $128.60 |
| 10 gram | 0.3215 | 10 | 0.35 oz | $1,286 |
| 1 oz | 1 | 31.10 | 1.10 oz | $4,000 |
| 10 oz | 10 | 311.0 | 0.69 lb | $40,000 |
| 1 kilo | 32.15 | 1,000 | 2.2 lb | $128,600 |
| 400 oz Good Delivery | about 400 | about 12,440 | about 27.4 lb | about $1.6 million |
Use the bullion weight tables and the gram to troy ounce converter to check any size.
The 400 oz bar is the standard in wholesale and central bank holdings. Bars that meet the London Bullion Market Association's Good Delivery standard must contain between roughly 350 and 430 troy ounces of gold and be at least 99.5% pure. Each bar is stamped with its refiner, serial number, weight and purity. Individuals rarely buy them, because of the cost, the weight (around 27 pounds) and the storage requirements, but they set the reference for the gold market. See LBMA Good Delivery explained.
A refiner has to make, stamp, package and ship each bar. Those costs are similar for a 1 gram bar and a 1 ounce bar, so as a share of the metal, they weigh far more on small bars. Dealers also add their margin. The result is that premiums fall as bar size grows.
| Bar size | Typical premium level | Best for |
|---|---|---|
| 1 g to 10 g | Highest | Gifts, first purchases |
| 1 oz | Moderate | Most individual buyers |
| 10 oz | Lower | Larger budgets |
| 1 kilo | Lowest for retail | Serious holders |
The right size depends on your budget and whether you'll ever want to sell part of it. See which gold bar size offers the best value and comparing coins and bars by cost per gram.
Example: a 1 oz bar quoted at $4,160 when spot is $4,000 carries a $160 premium, or 4%.
Bars usually have lower premiums than coins, but coins from national mints are easier to recognise and resell in small amounts. Read coins or bars first? and storing bars versus coins.
Larger bars should come with the assay certificate or sealed packaging that matches the bar's serial number. Do not break the seal unless you have to, as it can lower resale value. See how to authenticate a gold bar, how to read bar markings and why to keep the assay card.
A single kilo bar is a significant asset. Record its weight, serial number, cost and photos, and check your insurance. BullionKeeper stores these details with each holding and values them at the live price. See how to insure your collection.
A London Good Delivery gold bar weighs roughly 400 troy ounces, about 12.4 kilograms or 27.4 pounds. Actual bars vary between roughly 350 and 430 troy ounces, with a minimum gold purity of 99.5%.
A kilogram contains 32.15 troy ounces, so the cost is about 32.15 times the gold price per ounce, plus a premium. At an illustrative $4,000 per ounce that is roughly $128,600 before premium.
One ounce and 10 gram bars are popular for smaller buyers, while 10 oz and 1 kilo bars suit larger purchases. Smaller bars carry higher premiums per ounce, so cost per gram falls as bar size rises.
Per ounce, usually yes. Larger bars carry lower percentage premiums, but they are harder to sell in small amounts and need more cash upfront.
Multiply its weight in troy ounces by the current spot price, then add the dealer's premium. Compare that with the dealer's quoted price to see the premium you are paying.
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