Ring Size Guide: How to Measure, With Size Chart

Method one: measure a ring that fits

This is the more accurate method. Use a ring that is worn on the same finger of the same hand.

Lay the ring flat on a ruler.
Measure straight across the inside of the ring, from inner edge to inner edge, at its widest point.
Read the measurement in millimetres and find it in the diameter column of the chart below.

Cut a strip of paper about 10 cm long and 5 mm wide.
Wrap it around the base of the finger. It should be snug, and it must still slide over the knuckle.
Mark the point where the strip overlaps.
Lay the strip flat and measure to the mark in millimetres. That is the circumference. Find it in the chart below.

Measure three times and take the average. Fingers are a little larger at the end of the day and in warm weather, and smaller when they are cold.

European sizes are simply the inside circumference in millimetres. US sizes follow a scale in which each full size adds about 0.8 mm to the diameter.

US size	Inside diameter	Circumference	European size
3	14.1 mm	44.2 mm	44
3.5	14.5 mm	45.5 mm	45
4	14.9 mm	46.8 mm	47
4.5	15.3 mm	48.0 mm	48
5	15.7 mm	49.3 mm	49
5.5	16.1 mm	50.6 mm	51
6	16.5 mm	51.9 mm	52
6.5	16.9 mm	53.1 mm	53
7	17.3 mm	54.4 mm	54
7.5	17.7 mm	55.7 mm	56
8	18.1 mm	57.0 mm	57
8.5	18.5 mm	58.3 mm	58
9	18.9 mm	59.5 mm	60
9.5	19.4 mm	60.8 mm	61
10	19.8 mm	62.1 mm	62
10.5	20.2 mm	63.4 mm	63
11	20.6 mm	64.6 mm	65
11.5	21.0 mm	65.9 mm	66
12	21.4 mm	67.2 mm	67
12.5	21.8 mm	68.5 mm	68
13	22.2 mm	69.7 mm	70

Wide bands fit tighter. For a band wider than about 5 mm, go up half a size.
Mind the knuckle. If the knuckle is much larger than the base of the finger, choose a size between the two.
Hands differ. The same finger on the other hand can be half a size larger or smaller.
If it is a surprise, borrow a ring from the right finger for a minute and measure it with method one.

Every ART ring is made to order in your size. Tell us the measurement when you enquire, and if you are between sizes, say so.