Per Mille (Fineness)
Also: Parts per thousand, ‰, Millesimal fineness, Thousandths
Per mille (‰) states the fineness of a precious metal as a thousandths share of the total mass and is the legally binding designation on bars and coins.
Per mille (‰) is the unit of measurement for the fineness of a precious metal and states how many thousandths of the total mass consist of the pure metal. A gold bar bearing the marking 999.9 therefore contains 999.9 of 1,000 parts by weight of pure gold – the remainder being unavoidable trace elements. The per-mille figure is internationally standardised (ISO 9202) and has entirely replaced older carat markings on bars and industrial products.
Formula: calculating the fine weight
Fine weight = gross weight × (fineness ‰ / 1000)
Example: a 100 g bar with 585‰ contains 100 g × 0.585 = 58.5 g of fine gold. You can calculate the melt value directly with the melt value calculator.
Common finenesses at a glance
| Fineness (‰) | Carat equivalent | Metal | Typical use |
|---|---|---|---|
| 999.9 | — | Gold | Investment bars (Four Nines) |
| 999 | 24 carat | Gold | Coins (e.g. Maple Leaf, Panda) |
| 958 | — | Silver | Britannia silver (UK) |
| 950 | — | Platinum/Palladium | Investment bars, jewellery |
| 925 | — | Silver | Sterling silver (jewellery, cutlery) |
| 916 | 22 carat | Gold | Krugerrand, Sovereign |
| 835 | — | Silver | Historical coins (DE) |
| 800 | — | Silver | Historical coins (AT/CH) |
| 750 | 18 carat | Gold | High-quality jewellery |
| 585 | 14 carat | Gold | Central European jewellery |
| 375 | 9 carat | Gold | British jewellery |
| 333 | 8 carat | Gold | Basic gold jewellery (DE) |
The gold price overview and the silver price always refer to 999.9‰ pure metal – with lower fineness the material value falls proportionally.
Per mille vs. carat: the relationship
The carat system for gold is the older, Anglo-Saxon designation. The conversion is unambiguous:
Fineness (‰) = carat × 1000 / 24
24 carat therefore corresponds to 1,000‰ (theoretically pure gold); 18 carat gives exactly 750‰. In the UK the per-mille figure is used on hallmarks, and the carat value may be shown in addition.
Marking and legal significance
For a coin or bar to qualify as investment gold and benefit from the UK VAT exemption, HMRC criteria must be met. Under UK law, investment gold is VAT-exempt (HMRC; Directive 2006/112/EC): gold bars generally require a fineness of at least 995‰ (99.5%), and investment gold coins must meet the HMRC investment-gold coin criteria (minted after 1800, legal tender in the country of origin, of a purity of not less than 900‰ and normally sold at no more than 180% of the open-market value of the gold). Silver, platinum and palladium remain subject to the standard 20% VAT and do not benefit from this exemption. (Not tax or legal advice – for binding information, please consult a tax adviser.)
The hallmark – the engraved or stamped fineness mark – on a piece of jewellery or a bar is the visible proof of the per-mille value. In the UK, hallmarking of precious metal articles above certain weight thresholds is carried out by an Assay Office under the Hallmarking Act 1973. Independent assayers and refineries such as Heraeus or Umicore guarantee, with their company logo, compliance with the stated fineness.
Practical tip: buy-back and melt value
When selling gold, the payout price is always calculated on the basis of the fine weight, not the gross weight. Anyone selling old jewellery gold (e.g. 585‰) receives correspondingly less than for an investment bar (999.9‰). With the purchase price calculator you can determine the realistic proceeds in advance.
In brief
Per mille is the universal, legally standardised language of the precious metals trade: the higher the ‰ value, the greater the pure metal share and the closer the material value lies to the current spot price. For bars and investment coins, only purchases from 999‰ upwards are worthwhile – anything below contains alloying metals that must be deducted when melting.