Unlabeled

Inside diameter of a ring by U.S. ring size, 3 to 13

On the usual U.S. scale, each whole ring size adds 0.032 inch (0.81 mm) to the inside diameter: a size 3 ring is 14.1 mm across, a size 13 ring 22.2 mm.

What does this axis measure?
What does this axis measure?
Inside diameter of a ring by U.S. ring size, 3 to 13: 21 points, a line chart.
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Inner diameter (mm)
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Ring size (US size)
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The data: 21 points
Ring size (US size)Inner diameter (mm)
314.07
3.514.47
414.88
4.515.29
515.69
5.516.1
616.51
6.516.91
717.32
7.517.73
818.13
8.518.54
918.95
9.519.35
1019.76
10.520.16
1120.57
11.520.98
1221.38
12.521.79
1322.2
Source
Computed: the usual U.S. trade rule for ring sizes as stated by Wikipedia, Ring size (inside diameter = 0.8128 mm x size + 11.63 mm; no published standard gives it) via Circular of the Bureau of Standards No. 43 (1921), section VII (the article cites it; it reports the ring gauges of its time and does not state the rule)
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CC-BY-SA 4.0
Read
2026-10-30
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21 points as the puzzle showed them · line
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