The complete ring size guide

Know your ring size in five minutes. Get it right first time.

Three simple ways to measure at home, an on-screen sizer, and the full international conversion chart, precise to a hundredth of a millimetre.

Measure my finger See the full chart

80 sizes, 0000 to Z+6 6 national systems 0.01 mm precision

No ring sizer needed

Everything you need is already at home: a ruler, a strip of paper, or a ring you love.

Every country, one chart

UK, US, French, German, Japanese and Swiss sizes side by side, so buying abroad is easy.

Instant conversion

Type any measurement or size and see its exact match in all six systems.

Buy with confidence

Jeweller-tested tips on band width, cold hands and knuckles, so it fits the first time.

How to measure

Three ways to find your size, from quickest to most exact.

Pick whichever suits you. For an engagement or wedding ring, try two methods and check that they agree.

Method 01

Measure a ring that already fits

Quickest method

If you own a ring that fits the finger you're buying for, its inside diameter tells you your size.

Lay the ring flat on a millimetre ruler.
Measure straight across the middle, from inside edge to inside edge. Don't include the metal.
Find that number in the Inside Diameter (mm) column of the chart, or type it into the size finder.

Example: an inside diameter of 17.35 mm is a UK O, US 7.

Method 02

Wrap a paper strip around your finger

Takes 2 minutes

This measures your finger's circumference. Use paper rather than string, because string stretches and gives a size too big.

Cut a strip of paper about 10 cm long and 1 cm wide.
Wrap it around the base of your finger, snug but not tight. It should still slide over your knuckle.
Mark where the paper overlaps with a pen, then lay it flat.
Measure from the end to the mark in mm, then match it to the Inside Circumference column.

Measure three times and use the largest reading, since your finger size changes during the day.

Method 03

Use the on-screen ring sizer

No ruler neededMost accurate at home

Hold a ring you own against your screen and adjust the circle until it matches. We calibrate first with a coin from your pocket, so it works on any phone or monitor.

Hold a £1, 10p or 1p coin against the screen and resize the circle to match it.
Place your ring on the circle and adjust until the gold line sits just inside the band.
Read off your size in every system.

Open the on-screen sizer →

Before you buy

Six things jewellers wish everyone knew.

Measure at the end of the dayFingers are largest in the evening and when you're warm. Cold fingers shrink by up to half a size.
Mind the knuckleIf your knuckle is wider than the base of your finger, choose a size in between the two so the ring slides on.
Wide bands fit tighterFor bands 6 mm or wider, go up half a size. Most men's wedding bands are 6 to 8 mm.
Between sizes? Go upA ring that's slightly loose can be fixed with a sizing bead. A tight ring just won't get worn.
Hands aren't identicalYour dominant hand is often half a size larger. Measure the exact finger on the exact hand.
Some metals can't be resizedTungsten, titanium and ceramic rings usually can't be resized, so measure twice before you order.

Size finder

Got a number? We'll tell you your size.

Type in your measurement, or convert a size you already know into any other country's system.

What did you measure?

Ring diameter Finger circumference

Measurement

Unit

Tip: under 30 mm is usually a diameter, over 30 mm a circumference.

Your size

OUK & AU

Example shown. Enter a measurement to see yours.

US & CA: 7
FR & RU: 55¼
Germany: 17¼
Japan: 14
Switzerland: 15¼
UK & AU: O

Diameter 17.35 mm Circumference 54.51 mm

Show it in the chart

Step 1 · Calibrate

Match a coin

Screens differ in size, so we calibrate first. Choose a coin, hold it against the screen, and adjust until the gold circle is exactly the same size.

Your coin

Step 2 · Measure

Match your ring

Place a ring on the circle and adjust until the gold line sits just inside the band.

Ø 17.35 mm · UK O · US 7

International ring size chart

The complete chart, 0000 to Z+6.

Every ring size with its exact inside diameter and circumference, converted across six national systems.

Convert my size

Whole UK letter sizes Half & quarter sizes Your match

Swipe sideways to see all sizes

International ring size conversion chart
UKUK & Australia	Diametermm	DiameterInches	Circumferencemm	CircumferenceInches	USUS & Canada	EUFrench & Russian	DEGerman	JPJapanese	CHSwiss
–	9.91	0.390	31.13	1.22	0000	–	–	–	–
–	10.72	0.442	33.68	1.39	00	–	–	–	–
–	11.53	0.454	36.22	1.43	0	–	–	–	–
A	11.95	0.474	37.54	1.49	½	–	–	–	–
A½	12.18	0.482	38.26	1.51	¾	–	–	–	–
B	12.37	0.487	38.86	1.53	1	–	–	1	–
B½	12.60	0.496	39.58	1.56	1¼	–	–	–	–
C	12.78	0.503	40.15	1.58	1½	–	–	–	–
C½	13.00	0.512	40.84	1.61	1¾	–	–	–	–
D	13.21	0.520	41.50	1.63	2	41½	13½	2	1½
D½	13.41	0.528	42.13	1.66	2¼	–	–	–	–
E	13.61	0.536	42.76	1.68	2½	42¾	13¾	3	2¾
E½	13.83	0.544	43.45	1.71	2¾	–	–	–	–
F	14.05	0.553	44.14	1.74	3	44	14	4	4
F½	14.15	0.557	44.45	1.75	3⅛	–	–	–	–
F¾	14.25	0.561	44.77	1.76	3¼	–	–	–	–
G	14.36	0.565	45.11	1.77	3⅜	45¼	–	5	5¼
G¼	14.45	0.569	45.40	1.79	3½	–	14½	–	–
G½	14.56	0.573	45.74	1.80	3⅝	–	–	6	–
H	14.65	0.577	46.02	1.81	3¾	46½	–	–	6½
H½	14.86	0.585	46.68	1.84	4	–	15	7	–
I	15.04	0.592	47.25	1.86	4¼	47¾	–	–	7¾
I½	15.27	0.601	47.97	1.89	4½	–	15¼	8	–
J	15.40	0.606	48.38	1.90	4⅝	49	15½	–	9
J¼	15.53	0.611	48.79	1.92	4¾	–	–	–	–
J½	15.70	0.618	49.32	1.94	5	–	15¾	9	–
K	15.80	0.622	49.64	1.95	5⅛	50	–	–	10
K¼	15.90	0.626	49.95	1.97	5¼	–	–	–	–
K½	16.00	0.630	50.27	1.98	5⅜	–	–	10	–
L	16.10	0.634	50.58	1.99	5½	51¾	16	–	11¾
L¼	16.30	0.642	51.21	2.02	5¾	–	–	–	–
L½	16.41	0.646	51.55	2.03	5⅞	–	–	–	–
M	16.51	0.650	51.87	2.04	6	52¾	16½	12	12¾
M½	16.71	0.658	52.50	2.07	6¼	–	–	–	–
N	16.92	0.666	53.16	2.09	6½	54	17	13	14
N½	17.13	0.674	53.82	2.12	6¾	–	–	–	–
O	17.35	0.683	54.51	2.15	7	55¼	17¼	14	15¼
O½	17.45	0.687	54.82	2.16	7¼	–	–	–	–
P	17.75	0.699	55.76	2.20	7½	56½	17¾	15	16½
P½	17.97	0.707	56.45	2.22	7¾	–	–	–	–
Q	18.19	0.716	57.15	2.25	8	57¾	18	16	17¾
Q½	18.35	0.722	57.65	2.27	8¼	–	–	–	–
Q¾	18.53	0.729	58.21	2.29	8½	–	18½	17	–
R	18.61	0.733	58.47	2.30	8⅝	59	–	–	19
R¼	18.69	0.736	58.72	2.31	8¾	–	–	–	–
R½	18.80	0.740	59.06	2.32	8⅞	–	–	–	–
R¾	18.89	0.748	59.34	2.35	9	–	19	18	–
S	19.10	0.752	60.00	2.36	9⅛	60¼	–	–	20¼
S¼	19.22	0.757	60.38	2.38	9¼	–	–	–	–
S½	19.31	0.760	60.66	2.39	9⅜	–	–	–	–
S¾	19.41	0.764	60.98	2.40	9½	–	19½	19	–
T	19.51	0.768	61.29	2.41	9⅝	61½	–	–	21½
T¼	19.62	0.772	61.64	2.43	9¾	–	–	–	–
T½	19.84	0.781	62.33	2.45	10	–	20	20	–
U	20.02	0.788	62.89	2.48	10¼	62¾	–	21	22¾
U½	20.20	0.797	63.46	2.50	10½	–	20¼	22	–
V	20.32	0.800	63.84	2.51	10⅝	63	–	–	23¾
V¼	20.44	0.805	64.21	2.53	10¾	–	–	–	–
V½	20.68	0.814	64.97	2.56	11	–	20¾	23	–
W	20.76	0.817	65.22	2.57	11⅛	65	–	–	25
W¼	20.85	0.821	65.50	2.58	11¼	–	–	–	–
W½	20.94	0.824	65.78	2.59	11⅜	–	–	–	–
W¾	21.08	0.830	66.22	2.61	11½	–	21	24	–
X	21.18	0.834	66.54	2.62	11⅝	66¼	–	–	26¼
X¼	21.24	0.836	66.73	2.63	11¾	–	–	–	–
X½	21.30	0.839	66.92	2.64	11⅞	–	–	–	–
Y	21.49	0.846	67.51	2.66	12	67½	21¼	25	27½
Y½	21.69	0.854	68.14	2.68	12¼	–	–	–	–
Z	21.89	0.862	68.77	2.71	12½	68¾	21¾	26	28¾
Z+½	22.10	0.870	69.43	2.73	12¾	–	–	–	–
Z+1	22.33	0.879	70.15	2.76	13	–	22	27	–
Z+1.5	22.60	0.890	71.00	2.80	13.5	–	–	–	–
Z+2	22.69	0.893	71.28	2.81	–	–	–	–	–
Z+2.5	22.92	0.902	72.00	2.83	–	–	–	–	–
Z+3	23.06	0.908	72.45	2.85	–	–	–	–	–
Z+3.5	23.24	0.915	73.01	2.87	–	–	–	–	–
Z+4	23.47	0.924	73.73	2.90	–	–	–	–	–
Z+4.5	23.55	0.927	73.98	2.91	–	–	–	–	–
Z+5	23.87	0.940	74.99	2.95	–	–	–	–	–
Z+6	24.27	0.956	76.25	3.00	–	–	–	–	–

Inside diameter and circumference are measured on the inside of the band. – means no direct equivalent in that system.

Most common for women

UK J to N · US 5 to 7

avg UK L½

UK FKPUZ

Engagement rings are usually bought in UK L or M (US 6). If you're buying as a surprise, those are the safest place to start.

Most common for men

UK R to V · US 8½ to 11

avg UK T

UK FKPUZ

Men's wedding bands tend to be wider, so many men size up by half a size from their measured fit.

Questions

Ring sizing, answered.

The questions we're asked most often, answered in plain English.

How accurate is measuring my ring size at home?

All three methods will get most people to within half a size. The on-screen sizer is the most accurate at home, because you match your ring to a calibrated circle instead of reading a ruler by eye. Measuring a ring with a ruler is the quickest. The paper strip is the least precise, so if you use it, measure three times and use the largest reading. For an engagement or wedding ring, try two methods, or confirm with a jeweller's ring sizer.

What should I do if I'm between two sizes?

Choose the larger size. Your fingers swell in warm weather, after exercise and later in the day, and a slightly loose ring is much more comfortable than a tight one. This matters even more for wide bands.

Does the width of the band change my size?

Yes. A wide band covers more of your finger and feels tighter than a slim one in the same size. For bands 6 mm or wider, go up by half a size. For 8 mm and wider, many people go up a full size.

Are men's and women's ring sizes different?

No, there's only one sizing scale. A UK R is the same for everyone. Men's fingers are usually larger on average, so men's rings tend to be sold from around UK P upwards.

How can I find someone's ring size without them knowing?

Borrow a ring they wear on the same finger and measure its inside diameter (Method 01), or press it into a bar of soap to get a clear outline you can measure later. If you can't do that, UK L to M is the most common size for engagement rings. Just check the ring can be resized after the proposal.

Is my ring size the same on both hands?

Often not. Your dominant hand is usually up to half a size larger, and each finger is a different size. Always measure the exact finger on the exact hand where you'll wear the ring.

Can a ring be resized if it doesn't fit?

Most gold, silver and platinum rings can be resized by one or two sizes. Tungsten carbide, titanium, ceramic and full eternity rings usually can't, though many retailers offer a size exchange instead. Check before you buy.

Why do UK sizes use letters and US sizes use numbers?

Each country developed its own standard. The UK and Australia use letters A to Z in half steps, the US and Canada use numbers in quarter steps, and France uses the inside circumference in millimetres. The chart above lines them all up so you can convert with confidence.

Five minutes from now

You'll know your size. Then the fun part starts.

Grab a ruler or a strip of paper and let's get your size sorted.

Start measuring Open the chart