Gold Bar Purity and Weight: A Practical Guide to Grams and Troy Ounces
A gold bar’s weight tells you how much material it contains. Its purity tells you how much of that material is gold. Reading both figures together helps a first-time buyer understand a product description and gives a procurement team a consistent basis for comparing quotations.
Start with three details: the stated weight, the unit of measurement and the fineness. Then check how those details are recorded on the product and its supporting documents.
What do 995, 999 and 999.9 mean?
Fineness expresses gold content in parts per thousand. A fineness of 999.9 means 999.9 parts of gold in every 1,000 parts of material, equivalent to 99.99% gold. Similarly:
- 995 means 99.5% gold
- 999 means 99.9% gold
- 999.9 means 99.99% gold
Karat, also spelled carat in some markets, expresses gold purity on a scale of 24. For example, 18-karat gold contains 18 parts gold out of 24, or 75%. The World Gold Council’s guide to gold purity explains the relationship between karat and fineness.
For a bar quotation, request the numerical fineness alongside any “24-karat” description. It gives both parties a more precise specification to check.
How many grams are in a troy ounce?
Precious metals use the troy ounce. According to LBMA’s market definitions, one troy ounce equals 31.1034768 grams.
The conversion works in either direction:
- Grams to troy ounces: divide by 31.1034768
- Troy ounces to grams: multiply by 31.1034768
Using that conversion, 100 grams is approximately 3.215075 troy ounces, while one kilogram is approximately 32.150747 troy ounces. These rounded figures are useful for comparison; contractual weighing and rounding conventions should be agreed separately.
An ordinary household ounce uses a different weight system. When a listing says only “oz,” ask the seller to confirm that it means troy ounces. NIST’s precious-metals conversion guide is a useful reference for comparing measurement units.
Total bar weight and fine gold content
The weight of the metal bar, excluding packaging, includes both gold and any other material present. Fine gold content is the gold portion alone.
For a bar specified by total metal weight, the calculation is:
Fine gold content in grams = total metal weight in grams × fineness ÷ 1,000.
For example, a bar with a total metal weight of 100 grams and a fineness of 999.9 has a calculated fine gold content of 99.99 grams. At a fineness of 995, the same total metal weight gives 99.5 grams of fine gold. The difference is 0.49 gram.
These are illustrative calculations from the stated specifications. They do not authenticate a product or replace an assay. Also check whether a manufacturer’s advertised weight describes total metal weight or guaranteed fine gold content before applying the formula.
What does “Good Delivery” tell you?
LBMA Good Delivery has a specific scope. Its gold and silver lists concern refiners producing qualifying large bars for the London market. The relevant standards cover weight, purity and physical characteristics.
A small retail bar made by a listed refiner does not automatically become a London Good Delivery bar. LBMA explicitly distinguishes other refined products from the bars covered by its lists. Read LBMA’s explanation of Good Delivery before relying on that description in a quotation.
Ask which refiner made the product, which specification applies to the particular bar, and exactly what any accreditation claim covers.
Compare the specification with the documents
A useful product file links the item you receive to the description you agreed to buy. Before ordering, request written confirmation of:
- The manufacturer or refiner and product name.
- The stated weight, weight basis and unit.
- The numerical fineness.
- Any serial number or batch identifier used for that product.
- The assay or product documentation supplied with it.
- The seller’s process for handling a discrepancy.
Ask who issued any assay document and which bar, batch or sample it describes. Keep the invoice and relevant product records together. If a description is unclear, resolve it before treating two offers as equivalent.
Make quotations comparable
Use the same weight basis and fineness when comparing offers. Then review the complete quotation, including any stated fabrication premium, delivery charge or other applicable cost. A market reference price alone does not describe the delivered product; LBMA explains how form, size and fineness affect quotations.
When contacting Jawharat Al Khalij about a gold requirement, include your preferred bar size, fineness, quantity and delivery destination. You can review our precious metals services before preparing your enquiry.