Measurements

Most companies now measure the size of a piece of jewellery in millimetres. If you are unfamiliar with the metric system, use the chart below to ascertain the dimensions required:

1 mm = approximately 1/32" 21 mm = approximately 13/16"
2 mm = approximately 1/8" 22 mm = approximately 7/8"
3 mm = approximately 1/8" 23 mm = approximately 15/16"
4 mm = approximately 3/16" 24 mm = approximately 15/16"
5 mm = approximately 3/16" 25 mm = approximately 1"
6 mm = approximately 1/4" 26 mm = approximately 1"
7 mm = approximately 1/4" 27 mm = approximately 1 1/16"
8 mm = approximately 5/16" 28 mm = approximately 1 1/4"
9 mm = approximately 3/8" 29 mm = approximately 1 1/8"
10 mm = approximately 3/8" 30 mm = approximately 1 3/16"
11 mm = approximately 7/16" 31 mm = approximately 1 1/4"
12 mm = approximately 1/2" 32 mm = approximately 1 1/4"
13 mm = approximately 1/2" 33 mm = approximately 1 5/16"
14 mm = approximately 9/16" 34 mm = approximately 1 3/8"
15 mm = approximately 5/8" 35 mm = approximately 1 3/8"
16 mm = approximately 5/8" 36 mm = approximately 1 7/16"
17 mm = approximately 11/16" 37 mm = approximately 1 1/2"
18 mm = approximately 3/4" 38 mm = approximately 1 1/2"
19 mm = approximately 3/4" 39 mm = approximately 1 9/16"
20 mm = approximately 13/16" 40 mm = approximately 1 9/16"

Some common terms used in descriptions are:

Diameter: The length of a straight line passing through the centre of a circle from edge to edge.

Circumference: The measurement of the outer edge of a circle.