Ring sizes by brand
Each jeweller below prints its own ring size chart. Pandora and Cartier number rings by the inside circumference in millimetres, Swarovski adds one to that number, and Tiffany, Blue Nile, Brilliant Earth, Mejuri and Kay use US sizes. These pages show what each brand publishes; they are not affiliated with any brand.
How brands number rings
Most jewellers size rings in the scale of the country they sell in, so a US brand uses US numbers and a European brand the circumference in millimetres. A few use a number of their own, and the same figure on two brands can be two different rings.
The three brands with their own pages are the ones whose number is not the country’s: Pandora and Cartier use the circumference in millimetres, and Swarovski adds one to the European number. The others print US sizes and are listed below with what their charts say.
Each entry links the brand’s own chart, which is the authority: charts change, and the figures here are what the brand printed on the day shown.
Brands that publish a chart
Pandora ring size chart
Pandora size numbers give the ring’s inside circumference in millimetres. Size 54 matches ISO 54; the available chart is an older reference, so check Pandora’s current chart before buying.
Cartier ring size chart
Cartier’s size number is the ring’s inside circumference in millimetres. The size to buy can change by collection, so check the model’s adjustment before choosing.
Swarovski ring size chart
Swarovski’s size number uses its own scale: the EU number plus 1. Its chart covers whole sizes from 48 to 64, so check the current Swarovski chart if its sizing differs from this reference.
Tiffany & Co.
Tiffany & Co.’s chart uses the US scale, and the numbers here are US sizes. It prints US 4 to 13 in half steps, with inside diameters in millimetres. Its printed UK letters run about half a letter off the strict scale from US 7.5. The PDFs date from 2019, so the brand’s own current chart is the authority.
Brilliant Earth
The brand’s own current chart uses US sizes, and the numbers here are US sizes. It prints sizes 3 to 13 in quarter-size steps, with an inside-circumference column in millimetres for the full range. The chart is the authority for its published sizes.
Blue Nile
Blue Nile’s own chart uses US sizes and lists them through 13.5 in half steps, with inside diameters in millimetres. The brand says women’s rings come in sizes 3 through 9 and men’s in sizes 3 through 13, with custom sizing for other sizes. US 9 has different printed diameters in the web chart and PDF.
Mejuri
Mejuri’s chart uses US sizes and prints US 3 to 13, alongside UK letters. The brand’s current chart is the authority. It says half sizes are not offered, though the chart lists them, and its printed UK letters run half a letter off the strict scale from US 7.
Kay Jewelers
The brand’s current chart is the authority and uses US sizes, from US 3 to US 13.5 in half steps. Its notes describe matching a ring you wear with a printable chart, set to print at 100 percent; the chart also lists inside diameter in millimetres and centimetres.
Brand names are used only to describe the sizes each brand sells. RingSteps is not affiliated with, endorsed by or sponsored by any of them.