# Sheet Steel Weight & Thickness Chart

By Jack Gray, Roof Online Editor • Last updated September 8, 2022

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## What is Gauge when Talking about Sheet Steel?

When referring to metal, “gauge” is a standardized measurement of the thickness of the product in question, generally sheet steel, steel plate, or wire. Sheet steel thickness decreases as the gauge number increases.

There are a couple of explanations for the origin of gauge as a measure of sheet steel thickness, and why sheet steel thickness goes down while the gauge number goes up.

Both explanations start back in the early days of the Industrial Revolution in England, when new industrial standards were being created left and right.

New standards were needed to ensure that all of the new manufacturers of new industrial materials would be producing interchangeable products that their customers could rely on to be practically identical regardless of the producer.

These industry-wide standards gave a massive boost to efficiency. Standardization was one of the prime drivers of the Industrial Revolution.

One explanation of the origins of gauge as a measure of sheet steel weight and thickness says that the concept of gauge was borrowed from the wire industry.

Wire is produced by being drawn (essentially using machine tools to pull it through a hole to make it thinner). Wire gauge was determined by how many times a piece of wire was drawn through smaller and smaller holes. And the more times it was drawn, the thinner and lighter it was.

The wire industry standardized wire measurement by using the gauge system to specify the diameter of wire. So this explanation of sheet steel gauge says the sheet steel producers simply adopted the gauge system of weight and thickness from the wire industry.

The other explanation is that sheet steel manufacturers established a standard weight per square foot for a one-inch-thick steel plate, and then took this standard as a starting point. The sheet steel gauge number referred to how many sheets of a particular thickness would fit into an inch.

That is, sheet steel gauge referred to the fraction of an inch that the thickness of the sheet was. A 20-gauge sheet of steel would be 1/20 of an inch thick, and so on.

Sheet steel weight for a particular gauge number would simply reflect the standardized density of steel and the standardized thickness of that gauge number.

Over time, for one reason or another, so many sheet steel manufacturers began deviating from the standard that new standards had to be established to reflect reality.

That’s why current gauges aren’t precise fractions of an inch, and that’s how we got to where we are today. At least that’s the story.

## Manufacturers’ Standard Gauge for Sheet Steel

The table below provides sheet steel weights and thicknesses 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.

The Manufacturers’ Standard Gauge for Sheet Steel assumes an average density for carbon steel of 41.82 lbs. per square foot per inch thick. The precise thickness for each gauge is established by the standard. The standard sheet steel weight for each gauge number is derived from these standards.

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 the practicalities of 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.

### The Old Standard Sheet Steel Gauge

The U.S. Standard Gauge for Sheet and Plate Iron and Steel is not the same as the Manufacturers’ Standard Gauge and should not normally be referred to when calculating sheet steel weight. It is not generally used for commercial purposes any more.

If you’d like to take a look at the U.S. Standard Gauge (which is, in fact, a part of the U.S. legal code) see this page at the Cornell Law School website.

## Galvanized Sheet Steel Weight and Thickness

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 Sheet Steel Weight

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 exact 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.

## Sheet Steel Gauge Measuring Tool

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.

You can also see product information for sheet steel at the Home Depot.

## About These Sheet Steel Weights

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 sheet steel weights and thicknesses) are almost always made available on the websites of reputable manufacturers.

## Table: Sheet Steel Weights and Thicknesses

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
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
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
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