The following table provides sheet steel thicknesses and weights in both US and metric according to the Manufacturers’ Standard Gauge for Sheet Steel (MSG), which is the primary commercial gauge system used by sheet steel manufacturers in the United States today. When you buy sheet steel, these are typically the weights and thicknesses you’ll be getting, although actual finished products may vary slightly according to industry-accepted manufacturing tolerances (small variations from the standard due to practicality in the manufacturing process). These tolerances go from around (+-) 4.5% for 10 gauge steel to around 8.5% for 15 gauge steel and higher. (If these were rocket ship parts, the tolerances would be much, much smaller.) A full table of ASTM-AISI standard sheet steel tolerances by gauge number can be seen here.

For a look at the old legal “Standard Gauge for Sheet and Plate Iron and Steel”, which is not generally used commercially any more, see this page at the Cornell Law School website.

The Manufacturers' Standard Gauge for Sheet Steel assumes an average density for carbon steel of 41.82 lb per square foot per inch thick, and the standards for each gauge number are derived from that.

A piece of 24-gauge galvanized steel used to patch a rusted area of steel roof deck.

A piece of 24-gauge galvanized steel used to patch a rusted area of steel roof deck.

Galvanized steel is formed by applying a very thin coating of zinc to a steel sheet. Approximately the same amount of zinc is applied regardless of the gauge of the steel, so the thickness and weight of galvanized steel by gauge can be determined by adding a constant to the values for the plain steel gauges (see the table below).

Corrugated steel, which is used for roof decks and some roof and wall panels, will weigh from 30% to 70% more per square foot as a finished product than flat sheet steel of the same gauge due to the corrugation. The precise increase in weight depends on the depth and spacing of the ribs, which varies from product to product. The weight per square foot should be available on the website of the manufacturer.

The values provided in the table are standards; real-life products will vary. These values should not be used if extreme precision is needed for critical engineering calculations. When such precision is required, always refer to the data sheets of the actual, specific product you intend to use, or better yet, contact the technical department of the product manufacturer.

Manufacturer technical data sheets (with the material weights and thicknesses) are almost always made available on the websites of reputable manufacturers.

If you need to identify or verify the gauge of a piece of sheet steel (if you need to know the gauge of an existing steel roof deck, for example), see this useful and inexpensive tool on Amazon.*


Weight of Sheet Steel

Gauge Thickness:
Manufacturers' Standard Gauge
(Decimal Inches)
Weight:
Pounds per Square Foot (lb/ft2)
Thickness:
Manufacturer's Standard Gauge
(Millimeters)
Weight:
Kilograms per Square Meter
(kg/m2)
Examples of Use
Add 0.00375 for
Galvanized Steel
Add 0.156 for Galvanized Steel Add 0.095 for Galvanized Steel Add 0.762 for Galvanized Steel
3 0.2391
inch
10.000
lb/ft2
6.07
mm
48.824
kg/m2
house foundation bearing plate
4 0.2242
inch
9.375
lb/ft2
5.69
mm
45.773
kg/m2
automotive leaf spring
5 0.2092
inch
8.750
lb/ft2
5.31
mm
42.721
kg/m2
seawall panels, heavy retaining wall panels
6 0.1943
inch
8.125
lb/ft2
4.94
mm
39.670
kg/m2
machine tool housing/cabinet
7 0.1793
inch
7.500
lb/ft2
4.55
mm
36.618
kg/m2
saw mill blades
8 0.1644
inch
6.875
lb/ft2
4.18
mm
33.567
kg/m2
walls of large commercial grain bins
9 0.1495
inch
6.250
lb/ft2
3.80
mm
30.515
kg/m2
home safe, gun safe wall construction
10 0.1345
inch
5.625
lb/ft2
3.42
mm
27.464
kg/m2
residential storm shelter wall construction
11 0.1196
inch
5.000
lb/ft2
3.04
mm
24.412
kg/m2
weldable automobile frame patches
12 0.1046
inch
4.375
lb/ft2
2.66
mm
21.361
kg/m2
heavy duty eave struts in steel buildings
13 0.0897
inch
3.750
lb/ft2
2.28
mm
18.309
kg/m2
metal flooring plates
14 0.0747
inch
3.125
lb/ft2
1.90
mm
15.258
kg/m2
heavy duty corner angle/corner braces
15 0.0673
inch
2.813
lb/ft2
1.71
mm
13.734
kg/m2
tractor fenders
16 0.0598
inch
2.500
lb/ft2
1.52
mm
12.206
kg/m2
roof truss gusset plates, heavy gauge roof deck
17 0.0538
inch
2.250
lb/ft2
1.37
mm
10.985
kg/m2
steel wheelbarrow tub
18 0.0478
inch
2.000
lb/ft2
1.21
mm
9.765
kg/m2
medium gauge roof deck, traffic signs
19 0.0418
inch
1.750
lb/ft2
1.06
mm
8.544
kg/m2
auto body panels
20 0.0359
inch
1.500
lb/ft2
0.91
mm
7.324
kg/m2
medium gauge roof deck
21 0.0329
inch
1.375
lb/ft2
0.84
mm
6.713
kg/m2
workshop tool chest cabinet
22 0.0299
inch
1.250
lb/ft2
0.76
mm
6.103
kg/m2
light gauge roof deck
23 0.0269
inch
1.125
lb/ft2
0.68
mm
5.493
kg/m2
overhead/rolling door section panels
24 0.0239
inch
1.000
lb/ft2
0.61mm 4.882
kg/m2
metal parapet wall coping
25 0.0209
inch
0.875
lb/ft2
0.53
mm
4.272
kg/m2
corrugated metal roof panels
26 0.0179
inch
0.750
lb/ft2
0.45
mm
3.662
kg/m2
typical standing seam metal roof panels
27 0.0164
inch
0.688
lb/ft2
0.42
mm
3.359
kg/m2
foam composite garage door panel exterior skin
28 0.0149
inch
0.625
lb/ft2
0.38
mm
3.052
kg/m2
substrate for lightweight insulating concrete
29 0.0135
inch
0.563
lb/ft2
0.34
mm
2.749
kg/m2
lightest gauge standing seam metal roof panels
30 0.0120
inch
0.500
lb/ft2
0.30
mm
2.441
kg/m2
round sheet metal pipe for HVAC ducts
31 0.0105
inch
0.438
lb/ft2
0.27
mm
2.139
kg/m2
lightweight corrugated roof and wall panels
32 0.0097
inch
0.406
lb/ft2
0.25
mm
1.982
kg/m2
galvanized steel step flashings
33 0.0090
inch
0.375
lb/ft2
0.23
mm
1.831
kg/m2
residential plumbing vent roof jack
34 0.0082
inch
0.344
lb/ft2
0.21
mm
1.680
kg/m2
toy-making, model-building
35 0.0075
inch
0.313
lb/ft2
0.19
mm
1.528
kg/m2
shim stock for leveling machine parts
36 0.0067
inch
0.281
lb/ft2
0.17
mm
1.372
kg/m2
"
37 0.0064
inch
0.266
lb/ft2
0.16
mm
1.299
kg/m2
"
38 0.0060
inch
0.250
lb/ft2
0.15
mm
1.221
kg/m2
"