Gold
400 oz gold bar: the London Good Delivery bar explained
The "400 ounce" gold bar is the London Good Delivery bar, the unit central banks and bullion banks hold. Each bar contains between 350 and 430 troy ounces of fine gold (about 12.4 kg at 400 ounces), at a fineness of at least 995.0. At 400 fine ounces it held about USD 1.75 million of gold on 11 September 2026.
400 oz gold bar at a glance
| Item | London Good Delivery bar |
|---|---|
| Fine gold content | 350 to 430 troy ounces (about 10.9 to 13.4 kg); typically close to 400 oz |
| Weight at 400 oz | 12,441 g, or about 27.4 lb |
| Minimum fineness | 995.0 (99.5% gold) |
| Recommended dimensions | Top face 250 mm ± 40 mm long and 70 mm ± 15 mm wide; height 35 mm ± 10 mm |
| Required marks | Refiner's stamp, assay mark, fineness to four significant figures, serial number of up to 11 characters, and month and year of manufacture for bars made since January 2019 |
| Where it is traded | The London over-the-counter market, central-bank and bullion-bank vaults |
Why a 400 oz bar is rarely exactly 400 ounces
Good Delivery bars are cast from refined gold and then weighed and assayed, so each bar is stamped with its own weight and fineness. The rules allow any bar containing 350 to 430 fine ounces, and a bar's value depends on its fine gold content, not its gross weight. See gold bar sizes and weights.
How big is a 400 oz gold bar?
Gold's density is 19.3 g/cm³, so a 400 oz bar has a volume of about 645 cm³. That is roughly the size of a house brick cut in half lengthways, with the sloping sides the LBMA recommends so bars can be stacked and lifted.
What a 400 oz gold bar is worth
At the LBMA Gold Price PM of 11 September 2026 (USD 4,386.25 per troy ounce):
| Fine gold in the bar | Value of the gold content |
|---|---|
| 350 oz (minimum) | about USD 1,535,000 |
| 400 oz | about USD 1,754,500 |
| 430 oz (maximum) | about USD 1,886,000 |
The price changes every trading day. Wholesale Good Delivery bars trade close to the benchmark; see how much a gold bar is worth and how gold from Uganda is priced.
Who can make a Good Delivery bar
Only refiners on the LBMA Good Delivery List can produce bars that the London market accepts without re-assay. Bars from other refiners are "acceptable only after assay", and a buying refinery often treats them as feed for its own refining.
400 oz bars and gold from Uganda
No Ugandan refinery is on the LBMA Good Delivery List, so refined gold from Uganda is not supplied as 400 oz Good Delivery bars. Once our licensed supply route is in place, refined bars from Uganda would be quoted as 1 kg kilobars at 999.9 or 999.0, assayed on arrival. A buyer that needs Good Delivery bars can state this in the quote request, and the price basis reflects the refining step. See 1 kg gold bars, the gold bar specification, or request a gold quote.
Quotes
Tell us what you are buying.
Send the gold form, fineness, quantity, delivery point and the documents you require. We reply by email with what can and cannot be quoted at this stage, and on what basis.
Sources for the figures and rules on this page
Evidence for this page
Each statement is labelled by the strength of its evidence and dated. How we label evidence.
| Statement | Evidence | Source | Checked |
|---|---|---|---|
| LBMA Good Delivery gold bars contain 350–430 fine troy ounces (about 10.9–13.4 kg) at a minimum fineness of 995.0; recommended dimensions top length 250 mm ± 40 mm, top width 70 mm ± 15 mm, height 35 mm ± 10 mm; marks: refiner's stamp, assay mark, fineness to four significant figures, serial number of no more than 11 characters, month and year of manufacture for bars from January 2019. | Verified | LBMA Good Delivery Rules, technical specifications | |
| London takes only Good Delivery bars; non-Good-Delivery bars are acceptable only after assay and perhaps at a discount. | Verified | LBMA OTC Guide and Good Delivery guidance | |
| No Ugandan refinery appears on LBMA's Good Delivery List for gold. | Official | LBMA Good Delivery List, gold | |
| The density of gold is 19.3 g/cm³; one troy ounce is exactly 31.1034768 g. Values are fine ounces × USD 4,386.25 (LBMA Gold Price PM, 11 Sep 2026). | Inference | Royal Society of Chemistry; NIST Handbook 44; Uganda Gold Report calculation |