Fundamentals:
Dimensions of Copper

In building construction, copper is generally used in sheet and strip. Strip is 24 inches or less in width, while copper sheet is over 24 inches in width. Table 1.1.2 shows the standard dimensions of sheet and strip copper.

Table 1.1.2 - Typical Dimensions of Copper Sheet and Strip
Weight per S.F. in OuncesWidth InchesLength Inches
Sheet Copper 12 30, 36 96, 120
16 30, 36 96, 120
20 30, 36 96, 120
24 30, 36 96, 120
32 30, 36 96, 120
48 30, 36 96, 120
Strip Copper 16 10, 12, 14, 15, 16, 18, 20, 24 96, 120
20 20, 24 96, 120
24 20, 24 96, 120
32 20, 24 96, 120

The thickness of sheet and strip copper is measured by its weight in ounces per square foot. For example, the thickness of 12 ounce copper is such that every square foot weighs 12 ounces. The thicknesses commonly used in construction are between 8 and 32 ounces.

Since the industry often uses gauge numbers or actual thicknesses for sheet metal or other building materials, it is often necessary to convert between the different systems. Table 1.1.3 shows the relationship between the copper weight, thickness, and gauge number.

Table 1.1.3 Copper Weight, Thickness, and Gauge
Weight per Sq. Ft. Nearest Gauge No. (B&S)Thickness inches (mm)
OuncesPoundsNominalMinimum
6 .375 32 .0081 (.206) .0071 (.180)
8 .500 29 .0108 (.274) .0097 (.246)
10 .625 27 .0135 (.343) .0124 (.315)
12 .750 26 .0162 (.411) .0150 (.381)
16 1.00 23 .0216 (.549) .0204 (.518)
20 1.25 21 .0270 (.686) .0258 (.655)
24 1.50 20 .0323 (.820) .0308 (.782)
32 2.00 17 .0431 (1.09) .0411 (1.04)
48 3.00 14 .0646 (1.64) .0621 (1.58)