Gross weight × fineness, for platinum and palladium
A platinum or palladium bar carries two numbers that matter here: its weight and its fineness. Fineness is in parts per thousand, so a bar stamped 999.5 is 99.95% platinum or palladium by weight. The pure metal is the weight times the fineness divided by 1,000. A 1 oz platinum bar at 999.5 contains 0.9995 troy ounces of platinum, 31.088 g. A 1 kg bar at 999.5 contains 999.5 g, 32.135 troy ounces.
The same arithmetic serves both metals, so the calculator switches between them without changing anything else. Both are weighed in troy ounces of exactly 31.1034768 g, the same unit as gold and silver.
The LPPM Good Delivery plate and ingot
Wholesale platinum and palladium in London and Zurich are traded in plates and ingots made to the London Platinum and Palladium Market’s Good Delivery Rules. The rules, in their November 2023 edition, set the same physical limits for both metals: a minimum weight of 1 kilogram, 32.151 troy ounces, and a maximum of 6 kilograms, 192.904 troy ounces, at a minimum fineness of 99.95%.
Unlike the gold and silver Good Delivery bars, whose limits apply to the fine metal they contain, the LPPM limits apply to the plate or ingot’s own weight. The calculator compares the bar’s gross weight against them for that reason. Weights are stated to three decimal places of a troy ounce, or one decimal place in grams, and the rules say they should never be rounded up: extra decimal places from the scale are dropped, not rounded.
The comparison is with numbers only. A Good Delivery plate is also defined by the refiner being on the LPPM’s list and by its marks and finish, which no calculator can check. Retail bars of 1 oz, 10 g or 100 g are made to the refiner’s own specification and fall outside the wholesale range by design.
Fine weight is not a price
This page measures the metal; it does not value it. Bars are bought and sold at prices agreed between the parties, which can differ from the metal’s value at spot in either direction. For the value of the fine platinum or palladium at today’s price, use the platinum and palladium calculator with the fine weight shown here.
Whether a bar matches its stamp is a question for an assay. A refiner’s fineness mark is the refiner’s statement. Weighing the bar on an accurate scale is the first check anyone can make; anything further is a laboratory’s work, not arithmetic.