Ring Size Guide

Not sure of your ring size? Use this guide to find the right fit before you buy. All FoxnFound rings list their UK size in the product description.

Ring Size Converter

Enter a size in any system — we’ll find the closest match across all of them.

How to Measure Your Size

Method 1 — Measure a ring you already own

  1. Take a ring that fits well on the intended finger.
  2. Measure the inside diameter (straight across the inside of the band) with a ruler in millimetres.
  3. Enter it in the converter above, or find it in the chart below.

Method 2 — Measure your finger

  1. Cut a thin strip of paper (or use a piece of string).
  2. Wrap it snugly around the base of the finger you want to wear the ring on.
  3. Mark where the paper meets itself, then measure the length in millimetres — this is your circumference.
  4. Enter it in the converter above, or find it in the chart below.

Tips for Accuracy

  • Measure at the end of the day when fingers are at their largest.
  • Avoid measuring when fingers are cold (they’ll be smaller than usual).
  • If you’re between two sizes, go with the larger one for comfort.
  • For wide bands, consider going up half a size — wide rings sit tighter.
  • Measure two or three times — paper strips love to slip.

Vintage rings were often made before standard sizing, so we measure every ring by hand and state its UK size in the description. If a listing shows a size, that is the measured size of this exact piece.

International Ring Size Chart

UK, US and EU sizes compared by inside diameter and circumference in millimetres, following ISO 8653 guidance. The converter above uses this exact table.

UK / AU / NZ Inside Ø (mm) Circumference (mm) US / CA EU (ISO) IT / ES JP / CN
A 12.0 37.8 0.5 38
12.2 38.5 0.75 38
B 12.4 39.1 1 39
12.6 39.7 1.25 40
C 12.9 40.4 1.5 40 0.5 1
13.1 41.0 1.75 41 1 1
D 13.3 41.7 2 42 1.5 2
13.5 42.3 2.25 42 2.5 2
E 13.7 42.9 2.5 43 3 3
13.9 43.6 2.75 44 3.5 4
F 14.1 44.2 3 44 4 4
14.3 44.8 3.25 45 5 5
G 14.5 45.5 3.5 45 5.5 6
14.7 46.1 3.75 46 6 6
H 14.9 46.8 4 47 7 7
15.1 47.4 4.25 47 7.5 8
I 15.3 48.0 4.5 48 8 8
15.5 48.7 4.75 49 8.5 9
J 15.7 49.3 5 49 9.5 10
15.9 50.0 5.25 50 10 10
K 16.1 50.6 5.5 51 10.5 11
16.3 51.2 5.75 51 11 11
L 16.5 51.9 6 52 12 12
16.7 52.5 6.25 53 12.5 13
M 16.9 53.1 6.5 53 13 13
17.1 53.8 6.75 54 14 14
N 17.3 54.4 7 54 14.5 15
17.5 55.1 7.25 55 15 15
O 17.7 55.7 7.5 56 15.5 16
17.9 56.3 7.75 56 16.5 17
P 18.1 57.0 8 57 17 17
18.3 57.6 8.25 58 17.5 18
Q 18.5 58.3 8.5 58 18.5 18
18.7 58.9 8.75 59 19 19
R 18.9 59.5 9 60 19.5 20
19.2 60.2 9.25 60 20 20
S 19.4 60.8 9.5 61 21 21
19.6 61.4 9.75 61 21.5 22
T 19.8 62.1 10 62 22 22
20.0 62.7 10.25 63 22.5 23
U 20.2 63.4 10.5 63 23.5 24
20.4 64.0 10.75 64 24 24
V 20.6 64.6 11 65 24.5 25
20.8 65.3 11.25 65 25.5 25
W 21.0 65.9 11.5 66 26 26
21.2 66.6 11.75 67 26.5 27
X 21.4 67.2 12 67 27 27
21.6 67.8 12.25 68 28
Y 21.8 68.5 12.5 68 28.5
22.0 69.1 12.75 69 29
Z 22.2 69.7 13 70 29.5
22.4 70.4 13.25 70 30.5
Z+1 22.6 71.0 13.5 71 31
Z+1½ 22.8 71.7 13.75 72 31.5
Z+2 23.0 72.3 14 72 32.5
Z+2½ 23.2 72.9 14.25 73 33
Z+3 23.4 73.6 14.5 74 33.5

Not sure? Just ask — send us a message with your finger circumference in mm and we’ll confirm the right size for any ring in the shop.

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