Gauge Fit Guide
It can be confusing when some gauges are offered with millimeter(mm) sizes and other with inch sizes. Here’s how to navigate between them.
How to use: Column A is the measured millimeter size. Column C is the nearest inch size.
If you usually wear 18mm gauges, what would this be in inches?
Look down Column A for your usual millimeter size. Slide right along that row to see the nearest inch size in Column C: 11/16.
Then look in Column E to find out that the difference between the millimeter size and the inch size is .02”, 2 hundredths of a inch, such a small difference that both sizes will fit you.
(Columns B and D contain the mm and inch measurements converted to hundredths of an inch)
A = Millimeters sizes (measured by electronic calipers)
B = Millimeters converted to hundredths of a inch
C = Nearest size in inches
D = Inches converted to hundredths of an inch
E = Difference between mm size and inch size
A |
B |
C |
D |
E |
10mm |
.34” |
3/8 |
.38” |
.04” |
12mm |
.47” |
1/2 |
.50” |
.03” |
14 mm |
.55” |
9/16 |
.56” |
.01” |
16 mm |
.63” |
5/8 |
.63” |
.00” |
18 mm |
.71” |
11/16 |
.69” |
.02” |
20 mm |
.79” |
13/16 |
.81” |
.02” |
22 mm |
.87” |
7/8 |
.86” |
.01” |
24 mm |
.95” |
15/16 |
.94” |
.01” |