Gross Weight
Also: Total weight, Rough weight, Bulk weight
Gross weight is the total weight of a precious-metal object including all alloying components, before any deduction for impurities or additives.
Gross weight is the complete physical weight of a precious-metal object - that is, the weight a scale displays, with no allowance made for alloying components, impurities or foreign material. It stands in direct contrast to the fine weight, which describes only the actual precious-metal content. Anyone wishing to value gold jewellery, coins or scrap silver must understand this distinction.
Gross weight and fine weight in relation
The relationship between gross weight and fine weight can be described with one simple formula:
Fine weight = gross weight x fineness (as a decimal)
The fineness states what proportion of the gross weight consists of pure precious metal. In a gold alloy stamped 585 (14 carat), 58.5% of the gross weight is pure gold; the remaining 41.5% is alloying metals such as silver, copper or zinc.
| Alloy | Stamp | Fineness | Fine weight at 10 g gross |
|---|---|---|---|
| 8-carat gold | 333 | 33.3% | 3.33 g |
| 14-carat gold | 585 | 58.5% | 5.85 g |
| 18-carat gold | 750 | 75.0% | 7.50 g |
| 22-carat gold | 916.7 | 91.67% | 9.17 g |
| Fine gold | 999 | 99.9% | 9.99 g |
| Sterling silver | 925 | 92.5% | 9.25 g |
| Cutlery silver | 800 | 80.0% | 8.00 g |
Practical importance for buying and melt value
Dealers, refineries and pawnbrokers always quote prices on the basis of fine weight, not gross weight. Anyone selling scrap gold or silver jewellery therefore receives only the value of the precious metal actually present. The Melt Value Calculator works out the material-value figure directly from gross weight and stamp - the dealer's buying price is usually lower, because processing costs and margin are deducted.
Key steps in a valuation:
- Determine the gross weight on a calibrated precision scale (accuracy 0.01 g or better).
- Read off the stamp or hallmark and identify the fineness.
- Calculate the fine weight: gross weight x fineness.
- Multiply the fine weight by the current gold price or silver price.
Gross weight of coins and bars
For certified investment coins and LBMA Good Delivery bars, gross weight and fine weight are precisely defined and stated on the product. A one-ounce Krugerrand, for example, contains exactly 31.1035 g of fine gold (one troy ounce) but weighs around 33.93 g as a coin - the extra mass coming from the copper content (fineness 916.7/1000; 22 carat). Here the gross weight is measurably greater than the fine weight.
For fine bars (999.9), gross weight and fine weight are almost identical; the tiny difference lies within the manufacturer's permitted tolerance.
Distinction from related terms
- Fine weight: the calculated precious-metal content within the gross weight.
- Bulk weight (in a commercial context): may additionally include packaging or a container - do not equate it with gross weight, even though the terms are used loosely in everyday speech.
- Troy weight: the weight system used internationally in the bullion trade; one troy ounce equals 31.1035 g.
In brief
Gross weight is the starting value of every precious-metal valuation - only by multiplying by the fineness do you arrive at the value-relevant fine weight. Anyone buying or selling jewellery, coins or bars should always keep the two figures clearly apart and relate the current metal price to the fine weight.