Convert U.S. Standard sheet-steel gauge or AWG solid-wire gauge to inches, millimeters, and mils, or find the nearest gauge from a measured thickness or diameter.

Select the reference system and enter its gauge number.

U.S. Standard sheet/plate gauge (15 U.S.C. §206) differs from MSG commercial steel gauge. AWG applies to bare solid round wire. Confirm the system before comparing sizes.

U.S. sheet: 0–38. AWG: −3 to 40; −3, −2, −1 and 0 mean 4/0, 3/0, 2/0 and 1/0.

Gauge To Inches Formula

U.S. Standard sheet/plate gauge uses the nominal thickness table in 15 U.S.C. §206. AWG solid-wire diameter uses a geometric formula; neither system converts by dividing a gauge number by 39.37.

d(in) = 0.005 × 92⁽(36 − G) / 39) for AWG only

U.S. Standard sheet/plate values are a separate lookup, not MSG commercial sheet-steel values. For example, U.S. Standard gauge 16 is 0.0625 in; MSG steel gauge 16 is about 0.0598 in.

Variables:

  • d is the thickness or solid-wire diameter in inches
  • G is the gauge number

Select the exact gauge system. Look up U.S. Standard sheet/plate thickness, or evaluate the AWG formula for solid wire. Convert the resulting inch dimension to millimeters by multiplying by 25.4, or to mils by multiplying by 1,000.

U.S. Standard Gauge to Inches Conversion Table
Gauge (US) Thickness (in)
100.1406
110.1250
120.1094
130.0938
140.0781
150.0703
160.0625
170.0563
180.0500
190.0437
200.0375
210.0344
220.0312
230.0281
240.0250
250.0219
260.0187
270.0172
280.0156
290.0141
* Rounded to 4 decimals. Values per U.S. Standard Gauge; higher gauge numbers indicate thinner material.

What Does “Gauge to Inches” Mean?

Gauge to inches is a conversion method used to convert the thickness of a material measured in gauge number to inches. This is commonly used in industries such as manufacturing and construction, where materials like sheet metal, wire, or pipes are often measured in gauges. The gauge number and thickness in inches are inversely related, meaning a higher gauge number indicates a thinner material.

How to Calculate Gauge To Inches?

The following steps outline how to obtain inches from the selected gauge system.

  1. First, determine the gauge number (G).
  2. Next, use the U.S. Standard sheet/plate lookup or the AWG formula, as selected; gauge numbers are not metric dimensions.
  3. Finally, calculate the Gauge To Inches.
  4. After inserting the gauge number (G) and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

gauge number (G) = 16: U.S. Standard sheet/plate thickness = 0.0625 in (1.5875 mm).