Ring Size Converter
Convert ring sizes between US, UK, European and diameter measurements.
Sizing a ring across systems
Ring sizing uses different scales in different countries — a number in the US, a letter in the UK, a different number again in Europe — all describing the same finger. Buying a ring, especially as a gift or from abroad, means translating between them. This converts a ring size across the main systems and relates it to the actual diameter.
Enter a size in one system and see it in the others.
Measure, and mind the details
The reliable anchor beneath all the systems is the physical measurement — the inside diameter or circumference of the ring — which is what the sizes ultimately describe. A couple of practical tips make sizing more accurate: measure the finger when it is warm rather than cold, since fingers shrink in the cold, and remember a wide band sits tighter than a thin one, so it may need a slightly larger size. For a surprise gift, discreetly measuring a ring they already wear beats guessing from a converted number.
Ring Size Converter FAQ
What do the different ring size systems measure?
All describe the same finger via the ring's inside diameter or circumference, just on different scales — US numbers, UK letters, European numbers.
How can I size a ring accurately?
Measure the inside diameter of a ring that fits, and measure the finger when warm, since cold fingers shrink.
Is anything uploaded?
No. The conversion happens in your browser.