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A gold brick weighing 400 troy ounces has a mass of 12,441.39 grams, or about 12.44 kilograms and 27.43 ordinary pounds. “Brick” is an informal description, not a fixed size: a retail gold bar can be much smaller.
The familiar large vault bar is often called a 400-ounce bar, but that is a nominal description. Its actual weight and gold content must be read from its records. For the wholesale specification, see our 400-troy-ounce bar guide.
Gold bar weight comparison
These are unit conversions of the stated mass, rounded for comparison. They do not certify a particular product’s fine-gold content, purity or dimensions.
| Stated weight | Grams | Kilograms | Ordinary pounds |
|---|---|---|---|
| 1 troy ounce | 31.1035 | 0.03110 | 0.06857 |
| 10 troy ounces | 311.0348 | 0.31103 | 0.68571 |
| 100 grams | 100 | 0.10000 | 0.22046 |
| 1 kilogram | 1,000 | 1.00000 | 2.20462 |
| 400 troy ounces | 12,441.3907 | 12.44139 | 27.42857 |
Why a troy ounce matters
Gold uses the troy ounce. NIST’s precious-metal conversion chart gives one troy ounce as 31.1034768 grams. An ordinary ounce is about 28.35 grams. Using the ordinary ounce in a gold calculation understates the mass.
Troy ounces × 31.1034768 = grams. Divide grams by 1,000 for kilograms. For example, 400 × 31.1034768 ÷ 1,000 = 12.44139072 kg. The pounds in the table are everyday avoirdupois pounds, not troy pounds.
Gross weight and fine gold are different
Gross weight is the metal bar’s total mass, excluding packaging. Fine weight is its gold content after allowing for purity. A hypothetical 100-gram bar at 99.99% purity contains 99.99 grams of fine gold.
A product’s named weight may describe fine content rather than its exact gross mass. For example, the Perth Mint’s 1-kilogram cast bar specifies its gold content, purity and minimum gross weight separately. Read those fields rather than inferring all three from the product name.
How to check a bar’s stated weight
- Record the unit: grams, kilograms or troy ounces. Do not treat an unspecified “ounce” as sufficient documentation.
- Match the invoice and assay details to the bar, including the refiner and serial number where provided.
- Check whether the quoted mass includes packaging or refers to fine gold.
- Ask a qualified bullion professional about authentication. A matching weight alone does not establish that a bar is genuine.
Does the heaviest bar offer the best value?
Weight alone cannot answer that. Compare the total purchase price per fine troy ounce, then consider storage, insurance, delivery and the amount you would need to sell at once. A larger single bar cannot be partially sold without a further transaction or processing arrangement.
Use our gold-ingot value calculator and worked example to separate metal value from a dealer quote. For the buying process, read what to check before buying gold bars.
Educational information. Gold prices can fall, and a calculated metal value is not a purchase or resale quote. We may earn compensation through featured partners in our company directory; commercial relationships influence their placement.