Trothe
Find your ring size

Free tool

Ring size finder

Measure a ring you already own, or a strip of paper around the finger. Use the result as an estimate, then confirm the fit for the ring you choose.

Lay the ring flat and measure across the inside, edge to edge. Use a round ring that fits the intended finger and hand; a distorted ring needs a jeweller to measure it.

Still not sure?

Measure twice, on different days, at an ordinary room temperature, and choose by feel across the readings. For a wide band, half a size up is a common adjustment.

Every ring page shows the sizes it is made in, and our returns policy sets out what happens if a plain ring does not fit.

Measurement references: GIA's ring sizing advice and finger and ring measurement benchmarks. Explore band widths or resizing limits before choosing from the ring range.

Convert between UK, US and EU

The full UK size chart

Inner circumference and diameter in millimetres, with approximate US and European equivalents, for every whole UK letter. Half sizes sit between the letters either side.

UKCircumferenceDiameterUSEU
A 37.8 mm 12.03 mm 0.5 38
B 39.1 mm 12.45 mm 1 39
C 40.4 mm 12.86 mm 1.5 40.5
D 41.7 mm 13.27 mm 2 41.5
E 42.9 mm 13.66 mm 2.5 43
F 44.2 mm 14.07 mm 3 44
G 45.5 mm 14.48 mm 3.5 45.5
H 46.8 mm 14.90 mm 4 47
I 48.0 mm 15.28 mm 4.5 48
J 48.7 mm 15.50 mm 5 48.5
K 50.0 mm 15.92 mm 5.5 50
L 51.2 mm 16.30 mm 6 51
M 52.5 mm 16.71 mm 6.5 52.5
N 53.8 mm 17.13 mm 7 54
O 55.1 mm 17.54 mm 7.5 55
P 56.3 mm 17.92 mm 8 56.5
Q 57.6 mm 18.33 mm 8.5 57.5
R 58.9 mm 18.75 mm 9 59
S 60.2 mm 19.16 mm 9.5 60
T 61.4 mm 19.54 mm 10 61.5
U 62.7 mm 19.96 mm 10.5 62.5
V 64.0 mm 20.37 mm 11 64
W 65.3 mm 20.79 mm 11.5 65.5
X 66.6 mm 21.20 mm 12 66.5
Y 67.8 mm 21.58 mm 12.5 68
Z 69.1 mm 22.00 mm 13 69

Sizing questions

What is the most accurate way to find a ring size at home?
Measure a ring that already fits the same finger: its inside diameter, straight across the centre, gives your size from the chart on this page. A paper strip around the base of the finger works too, wrapped snugly and measured to the mark. A ring is the better of the two, because paper can stretch and a ring already shows how it passes the knuckle.
Does the time of day matter?
Yes, a little. GIA notes that temperature and time of day change finger size, so fingers read slightly larger when warm and smaller when cold. Measure at an ordinary room temperature, on two different days, and choose by how the ring feels across the range rather than automatically picking the largest.
What if my knuckle is larger than my finger?
Size for both. The ring has to slide over the knuckle with a little resistance and still sit securely at the base without spinning. Select the knuckle option above and the finder flags it, so you can check a ring you own passes the knuckle as well as fitting the base.
Do wider rings need a bigger size?
Often, yes. A wide band covers more of the finger, so it can feel snugger than a narrow ring at the same size, and half a size up is a common adjustment for wide bands. A comfort fit, curved rather than flat inside, eases that too.
How do I find someone's size without asking?
Borrow a ring they wear on the same finger and measure its inside diameter across the centre, then read the size from the chart on this page. Our guide to finding a ring size in secret has more ways to do it without giving the surprise away.