Everyday
Ring Size Calculator
Convert ring inner diameter or circumference to US, UK, and EU sizes.
Inputs
Ring Size Calculator
Result
US size
7
- UK size
- N
- EU size
- 54.3
- Inner diameter
- 17.3 mm
- Circumference
- 54.35 mm
How it's calculated
US ≈ (circumference − 36.5) / 2.55; EU = circumference (mm); UK letter step = 1.25 mm from A (37.8 mm)
Common questions
How do I measure my finger at home?
Wrap a strip of paper around the base of the finger, mark where it overlaps, and measure the length in mm. Do it warm — cold fingers shrink.
Which finger do I measure?
Measure the exact finger you'll wear the ring on. Dominant-hand fingers are usually a half size larger than the equivalent finger on the other hand.
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