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UK / Ireland / Australia

UK Ring Size Chart

The complete UK ring size guide — alphabetical letter sizes from A to Z and beyond, with full US, EU and mm conversions.

SizeRings.com › UK Ring Size Chart

The UK ring sizing system uses letters of the alphabet — A through Z, and then Z+1, Z+2, and so on for larger sizes. The same system is used in Ireland, Australia, New Zealand, and South Africa. Each step represents approximately 1.25mm of circumference.

UK Ring Size Conversion Chart

UK / IRE / AUSUS / CanadaEUJapanDiameter (mm)Circumference (mm)
F344414.144.2
G3.545514.545.6
H446.5714.946.8
I4.548815.348.0
J549915.749.3
K5.550.51116.150.6
L651.51216.551.9
M6.5531316.953.2
N7541417.354.4
O7.555.51617.755.7
P8571718.257.2
Q8.5581818.558.2
R9591918.959.3
S9.5612119.461.0
T10622219.862.2
U10.563.52420.263.5
V11652520.765.0
W11.5662621.166.2
X1267.52821.567.5
Y12.568.52921.968.8
Z13703022.370.1
Z+214713122.771.3

How UK Ring Sizes Work

In the UK system, each letter corresponds to a specific inside circumference. The letters run alphabetically but skip some letters (there is no UK size I, for example, in common use). Half sizes are occasionally used between letters but are less common than in the US system.

Average UK women's ring sizes tend to fall between J and N, with L–M being the most common. Average men's sizes run from R to W, with T–U being typical.

Converting UK to US Ring Sizes

There is no simple mathematical formula between UK letters and US numbers — you must use a chart. As a quick reference:

  • UK J ≈ US 5
  • UK L ≈ US 6
  • UK N ≈ US 7
  • UK P ≈ US 8
  • UK R ≈ US 9
  • UK T ≈ US 10

How to Measure for UK Ring Sizes

UK sizes are based on circumference, so to find your UK size:

  1. 1
    Wrap a paper strip around your finger

    Ensure it sits snugly at the base and passes over the knuckle.

  2. 2
    Mark and measure in mm

    This gives your circumference. For example, 54mm circumference = UK size N.

  3. 3
    Match to the chart above

    Find your circumference in the Circumference column and read the UK letter in the first column.

Shopping from a UK retailer from abroad? Use the chart above to find your UK letter equivalent from your US number or EU size. Always confirm with the retailer — some international brands use slight variations in their size scales.

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