US Ring Size 8 in mm (Diameter & Circumference)

US ring size 8 = 18.13 mm inner diameter, 57 mm circumference (UK P½, EU 57, JP 16)

US/CAUK/AUEU/ISOJPDiameterCircumference
7N½54.51417.32 mm54.4 mm
7.5O½55.51517.73 mm55.7 mm
8P½571618.13 mm57 mm
8.5Q½581718.54 mm58.2 mm
9R½59.51818.95 mm59.5 mm

FAQ

What is ring size 8 in mm?

About 18.13 mm across the inside, 57 mm around.

What is US 8 in UK size?

About P½.

Related

Sizes vary by brand and seller. Always check the product's own size chart and measure yourself; this chart is a general standard guide.