How to measure your ring size at home

Two reliable ways — one if you already have a ring that fits, one if you don't. Measure in millimetres, then convert below. Accuracy matters most for rings that can't be resized.

Best: measure a ring you own

Take a ring that fits the right finger and measure its inner diameter across the middle, in millimetres. Match that number to the Ø mm column on the chart, or type it into the converter as “Diameter (mm)”. This is the most accurate home method — no stretch, no knuckle error.

No ring? Use a paper strip

Wrap a thin strip of paper around the base of your finger, mark the overlap, and measure the length in millimetres. That's your circumference — enter it below. Avoid string or thread: they stretch and read half a size to a full size too large.

Convert your measurement

Have a millimetre measurement? Enter it here:

I know my size in Value

Your size is US 7 (UK N½, EU 54).

Fit confidence Exact table match

Measurement confidence 68/100 · Medium Finger circumference can shift with string tension, temperature and swelling. Measure again later in the day or verify with a printable sizer.

US: 7
UK: N½
EU / ISO: 54
Japan: 14
CH / IT / ES: 14
Ø mm: 17.32
Circ mm: 54.4

Open US 7 size guide

Print Smart rings Wallet Physical sizer Local only; no account.

US	UK	EU	JP	CH	Ø mm	Circ mm
3	F½	44	4	4	14.07	44.2
3.5	G½	45	5	5	14.48	45.5
4	H½	47	7	7	14.88	46.8
4.5	I½	48	8	8	15.29	48.0
5	J½	49	9	9	15.70	49.3
5.5	K½	51	10	11	16.10	50.6
6	L½	52	12	12	16.51	51.9
6.5	M½	53	13	13	16.92	53.1
7	N½	54	14	14	17.32	54.4
7.5	O½	56	15	16	17.73	55.7
8	P½	57	16	17	18.14	57.0
8.5	Q½	58	17	18	18.54	58.3
9	R½	60	18	20	18.95	59.5
9.5	S½	61	19	21	19.35	60.8
10	T½	62	20	22	19.76	62.1
10.5	U½	63	22	23	20.17	63.4
11	V½	65	23	25	20.57	64.6
11.5	W½	66	24	26	20.98	65.9
12	Y	67	25	27	21.39	67.2
12.5	Z	68	26	28	21.79	68.5
13	Z½	70	27	30	22.20	69.7

The five steps (no-ring method)

Cut a thin paper strip. Cut a strip of paper or use a length of non-stretch string about 10 cm long and a few millimetres wide.
Wrap it around the base of your finger. Wrap snugly around the base of the finger where the ring will sit — not over the knuckle yet. It should be comfortable, not tight.
Mark and measure. Mark where the strip overlaps and measure the length in millimetres with a ruler. That length is your finger circumference.
Check it passes the knuckle. Make sure a ring that size would still slide over your knuckle. If your knuckle is much larger, size up slightly.
Convert the measurement. Enter the circumference in millimetres in the converter to get your US, UK, EU and Japanese size.

Between sizes? Size up. A slightly loose ring is wearable and can be padded; a ring that's too tight may never pass the knuckle. Wide bands (≥6 mm) fit tighter — add a quarter to half size.

What makes home measurements wrong

String stretches. It compresses skin and slides over the knuckle — use a stiff paper strip or an existing ring.
Time of day & temperature. Fingers are smallest in the cold morning, largest when warm in the evening (up to ½ size).
The knuckle. The ring must pass it. If your knuckle is much larger, consider sizing beads rather than oversizing.
Band width. Wide and comfort-fit bands run tighter — size up slightly.
International charts vary. Japan, India and UK letters can differ by a full size — order by mm when you can.

Buying an engagement ring or a non-resizable ring? Confirm with a jeweler or a physical ring sizer before ordering — home methods are approximate.

Frequently asked questions

What is the most accurate way to measure ring size at home?

Measure the inner diameter of a ring that already fits well, in millimetres, and match it on the chart. This avoids the stretch and knuckle error of the string method.

When is the best time of day to measure?

Measure at the end of the day when your fingers are at their largest and warm. Fingers shrink in the morning and in cold weather by up to half a size.

How can I measure ring size without any tools?

Use a strip of paper: wrap it around the base of your finger, mark the overlap, and measure the length in mm — that is your circumference. A free printable ring sizer is more accurate.

Should I size up or down if I am between sizes?

Size up. A slightly loose ring is wearable and can be padded; a too-tight ring may not pass the knuckle. Wide bands fit tighter, so size up for them.

Next: print a free ring sizer or see the full size chart.