Ring sizing is a fairly straight-forward process, and one of the most commonly used by the bench jeweler. It involves either adding or removing a piece of metal from the shank of a ring to increase or decrease the diameter, or ring size. 2.61mm added to or removed from the shank will change the ring by one full size (US sizes). There are a variety of techniques used to affect the size of a ring.

Reading The Finger Size Of A Ring On A Calibrated Ring Mandrel

When a ring is offered at a specific finger size and it is stated in the item description, OR when a customer requests a finger size, the ring should be at the stated or requested size but is allowed to have a 1/8th finger size tolerance (up or down).

NOTE: The ring mandrel is marked in 1/4 sizes. 1/8 would be exact center between the 1/4 markings.

UNDER 6MM

When a ring is under 6 mm wide, the bottom edge of the ring should fall on the line for the rquested size.

Here are some visual exmples of how a ring under 6 mm in width should be read if an exact size 6 is requested:

NOTE: Remember, for a ring under 6 mm in width, you look at where the bottom edge of the ring falls on a mandrel.

Ideal

A ring that is an
exact size 6

Ring Sizing Example

Acceptable

A ring that is 1/8
smaller than a size 6

Ring Sizing Example

Acceptable

A ring that is 1/8
larger than a size 6

Ring Sizing Example

Unacceptable

A ring that is 1/4
smaller than a size 6

Ring Sizing Example

Unacceptable

A ring that is 1/4
larger than a size 6

Ring Sizing Example

6MM & OVER

When a ring is 6 mm or wider, the middle of the ring should fall on the line for the requested size.

Here are some visual exmples of how a ring 6 mm & over in width should be read if an exact size 6 is requested:

NOTE: A section of the ring was cut out to help you visually see where the center of the ring should fall on the mandrel.

Ideal

A ring that is an
exact Size 6

Ring Sizing Example

Acceptable

A ring that is 1/8
smaller than a size 6

Ring Sizing Example

Acceptable

A ring that is 1/8
larger than a size 6

Ring Sizing Example

Unacceptable

A ring that is 1/4
smaller than a 6

Ring Sizing Example

Unacceptable

A ring that is 1/4
larger than a 6

Ring Sizing Example

RING SIZE REFERENCE

Place your ring over the circles, matching the inside edge of the ring to the nearest in size. If the ring falls between two sizes, select the larger size.

Ring Sizing Example
Ring Sizing Reference Chart

RING BLANKS LENGTHS CHART

Ring Finger Size
(US)		 Diameter
(mm)		 Length
(mm)		 2.0 mm 1.6 mm 1.3 mm 1.0 mm .80 mm .60 mm .50 mm
1 12.44 39.09 45.29 44.09 43.09 42.09 41.49 40.89 40.59
1.5 12.85 40.37 46.57 45.37 44.37 43.37 42.77 42.17 41.87
2 13.26 41.64 47.84 46.64 45.64 44.64 44.04 43.44 43.14
2.5 13.66 42.92 49.12 47.92 46.92 45.92 45.32 44.72 44.42
3 14.07 44.20 50.40 49.20 48.20 47.20 46.60 46.00 45.70
3.5 14.47 45.47 51.67 50.47 49.47 48.47 47.87 47.27 46.97
4 14.88 46.75 52.95 51.75 50.75 49.75 49.15 48.55 48.25
4.5 15.29 48.03 54.23 53.03 52.03 51.03 50.43 49.83 49.53
5 15.69 49.30 55.50 54.30 53.30 52.30 51.70 51.10 50.80
5.5 16.10 50.58 56.78 55.58 54.58 53.58 52.98 52.38 52.08
6 16.51 51.86 58.06 56.86 55.86 54.86 54.26 53.66 53.36
6.5 16.91 53.13 59.33 58.13 57.13 56.13 55.53 54.93 54.63
7 17.32 54.41 60.61 59.41 58.41 57.41 56.81 56.21 55.91
7.5 17.73 55.69 61.89 60.69 59.69 58.69 58.09 57.49 57.19
8 18.13 56.96 63.16 61.96 60.96 59.96 59.36 58.76 58.46
8.5 18.54 58.24 64.44 63.24 62.24 61.24 60.64 60.04 59.74
9 18.95 59.52 65.72 64.52 63.52 62.52 61.92 61.32 61.02
9.5 19.35 60.79 66.99 65.79 64.79 63.79 63.19 62.59 62.29
10 19.76 62.07 68.27 67.07 66.07 65.07 64.47 63.87 63.57
10.5 20.16 63.35 69.55 68.35 67.35 66.35 65.75 65.15 64.85
11 20.57 64.63 70.83 69.63 68.63 67.63 67.03 66.43 66.13
11.5 20.98 65.90 72.10 70.90 69.90 68.90 68.30 67.70 67.40
12 21.38 67.18 73.38 72.18 71.18 70.18 69.58 68.98 68.68
12.5 21.79 68.46 74.66 73.46 72.46 71.46 70.86 70.26 69.96
13 22.20 69.73 75.93 74.73 73.73 72.73 72.13 71.53 71.23
13.5 22.60 71.01 77.21 76.01 75.01 74.01 73.41 72.81 72.51
14 23.01 72.29 78.49 77.29 76.29 75.29 74.69 74.09 73.79
14.5 23.42 73.56 79.76 78.56 77.56 76.56 75.96 75.36 75.06
15 23.82 74.84 81.04 79.84 78.84 77.84 77.24 76.64 76.34

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