Beyond the watch · Measure

The Smiths Sizer

Strap width, ring size, watch case and wrist — at their true size on your screen, whatever the device.

Recognising your screen…

Strap width16 – 24 mm, or anything between
Ring sizeEU, US, UK, Italy and Japan
Watch caseLay the watch on the screen
Wrist & braceletWith a strip of paper

How it stays true to size

01It recognises your screen
Your browser never says how big your screen is — but it does share its exact shape and, on most phones, the model. The sizer matches them against the makers’ published dimensions for hundreds of phones, tablets and Macs, so it opens at true size with nothing to set. If two models share a shape, you tap yours once.
02Lay it on the screen
Your strap, ring or watch, flat on the glass. Look straight down and move the line until it just touches the edge — drag it, or turn the crown below for the fine adjustment.
03Read the size — and keep it
The size appears at once, in every system. Save it as an image or share it — it carries the Smiths mark.

Ring size chart

There’s no single Gulf ring-size system: many jewellers use EU (the finger’s circumference in mm), others use US — so we always print the system next to the number. Between two sizes? Choose the larger.

EU · ISO circ. mm	Ø inner mm	US	UK	IT · ES · CH	JP
41	13.05	1¾	D	1	1
42	13.37	2¼	D½	2	2
43	13.69	2½	E½	3	3
44	14.01	3	F	4	4
45	14.32	3¼	G	5	5
46	14.64	3¾	H	6	6
47	14.96	4	H½	7	7
48	15.28	4½	I½	8	8
49	15.60	5	J	9	9
50	15.92	5¼	K	10	10
51	16.23	5¾	L	11	11
52	16.55	6	L½	12	12
53	16.87	6½	M½	13	13
54	17.19	6¾	N	14	14
55	17.51	7¼	O	15	15
56	17.83	7½	P	16	15
57	18.14	8	P½	17	16
58	18.46	8½	Q½	18	17
59	18.78	8¾	R	19	18
60	19.10	9¼	S	20	19
61	19.42	9½	T	21	20
62	19.74	10	T½	22	21
63	20.05	10¼	U½	23	22
64	20.37	10¾	V	24	23
65	20.69	11¼	W	25	24
66	21.01	11½	X	26	25
67	21.33	12	X½	27	26
68	21.65	12¼	Y½	28	27
69	21.96	12¾	Z	29	28
70	22.28	13	Z+1	30	29
71	22.60	13½	Z+2	31	30
72	22.92	14	Z+2½	32	—

Sources: ISO 8653:2016 (EU), the industry US formula, the BS 6820 metric scale (UK) and the Japan Jewellery Association JCS scale.

Strap widths, simply

A strap’s width at the watch end equals the gap between the watch’s lugs, in whole millimetres. 18, 20 and 22 mm are the common sizes; some vintage and independent watches use odd ones — 19, 21, 23. Most Smiths straps are quick-release.

Measure your strap All straps

Questions

Is it really accurate?

Yes. It works from each screen’s published dimensions — Apple’s, Samsung’s, Google’s and the other makers’ — so a millimetre on the screen is a real millimetre: typically within 1%, about a fifth of a millimetre at strap sizes. Lay the item flat and look straight down at it.

Why doesn’t it need a card or a ruler?

Because your screen’s size is already known. Browsers don’t tell a website how big a screen physically is, but they do share its exact shape and, on most phones, the model — and every maker publishes its screens’ dimensions. The sizer puts the two together. Only when it can’t recognise a device does it ask you to choose the model, or to type the screen size.

Is anything about me stored?

No. The sizer reads only what every browser already shares — the screen’s size in pixels and, where offered, the model name. A model you choose is saved on this device alone, and your measurements are never sent to us.

Which ring sizes do jewellers in Kuwait use?

There isn’t one system across the Gulf. Many jewellers use EU sizes — the finger’s circumference in millimetres — and others use US sizes. The sizer shows both, with UK, Italian and Japanese, so take the EU number and the millimetres with you.

What strap length do I need?

Most strap makers size by wrist: under about 16.5 cm, a short strap; about 16.5 to 19 cm, a regular one; above about 19 cm, a long one. Measure your wrist with the paper-strip tool.

Does it work on a computer or tablet?

Yes. iPads, Android tablets and MacBooks are recognised like phones. On a Windows or other computer, choose the screen’s size once — or scan the code and measure on your phone. Keep the browser at 100% zoom while you measure.

Who is it for?

What style suits them?

What would you like to spend?

The Smiths Sizer

How it stays true to size

Ring size chart

Strap widths, simply

Questions