Hallmark Calculator
A piece's purity is the same everywhere — 18-carat gold is 75% gold in every country. What changes is the mark struck on it, the name it's given, and whether an independent office tested it. Pick what you've got and where you're headed, and this shows you the rest.
United Kingdom
Independent assay
18-carat750 · 75% gold
Independently tested by an assay office before sale.
Look for
- Leopard's Head
- Anchor
- Rose
- Three-towered Castle
Which countries share each standard
Gold standards, side by side
Fineness (parts per thousand) is the universal measure — the calculator pivots on it. Where a grade you know isn't a legal standard in another country, it shows the nearest one rather than a false match.
A reference guide, not an authentication service. Marks and standards vary by date and metal; consult the relevant assay office or standards body for definitive identification.