Ring size guide

RING SIZE CONVERSION CHART BY FORMÉS

FORMES Ring Size Guide

Finding your ring size should feel as effortless as slipping on your favorite piece. Whether you're choosing a gift or treating yourself, here's how to get the perfect fit at home.

Two Simple Ways to Find Your Ring Size

1. Measure Your Finger

Take a soft ribbon, string, or strip of paper and wrap it gently around your finger. Make sure it slides comfortably over your knuckle.
Mark where it overlaps and measure the length in millimeters.
That number is your finger’s circumference. For example, 54 mm means size EU 54.

Tip: If you're between sizes, go one size up. If you’re choosing a slim ring, you can opt for a slightly smaller size.

2. Measure a Ring You Already Own

Pick a ring that fits the intended finger.
Lay it flat and measure the inside diameter in millimeters across the widest point.
Match this diameter to our size chart.

Sample of size 15, or 15 mm inner diameter

Helpful Sizing Tips

Fingers on your dominant hand are usually a bit bigger.
Warm weather = slightly larger fingers; cold = slightly smaller.
Wide bands (6mm+) feel tighter—go half a size up.
Slim stacking rings? Choose a snug fit.

how to measure a ring size by Formes Fine Jewelry

Ring Size Conversion Chart

Diameter (mm)	Circumference (mm)	EU Size	US Size	UK Size	Japan Size
14.0	44	44	3	E	4
14.4	45	45	3¼	F	5½
14.7	46	46	3¾	G	6
15.0	47	47	4	H	7
15.3	48	48	4½	I	8
15.6	49	49	5	I½	9
15.9	50	50	5¼	J	10
16.2	51	51	5¾	K	11
16.5	52	52	6	L	12
16.9	53	53	6¼	M	13
17.3	54	54	7	N	14
17.5	55	55	7¼	N½	15
17.8	56	56	7½	O	16
18.2	57	57	8	P	16½
18.6	58	58	8½	Q	17
18.8	59	59	8¾	R	18
19.1	60	60	9	R½	18½
19.4	61	61	9½	S	19
19.8	62	62	10	T	20
20.2	63	63	10¼	U	21
20.6	64	64	10¾	V	22
20.8	65	65	11	V½	23
21.0	66	66	11½	W	24
21.3	67	67	12	X	25
21.8	68	68	12½	X½	26
22.1	69	69	12¾	Z	27
22.3	70	70	13	Z+1	28
22.6	71	71	13½	Z+2	29

What About Ring Style?

Statement rings: If bold and wide, go half a size up.
Stacking rings: Measure the exact finger and go for a snug fit.
Knuckle/midi rings: These often run small—check specific design notes.
Engagement and wedding bands: Precision matters. Measure carefully or contact us for help.
Open rings: These are slightly adjustable but still follow our sizing guide.

Still Unsure? Let Us Help. Just message us—we're happy to guide you personally. And remember, FORMES rings can be resized or exchanged within 30 days for your peace of mind.