Metal Roofing Gauge Chart: Thickness and Weight per Foot

Quick numbers: .032 aluminum weighs about 0.45 lb per square foot. Nominal 24 gauge steel weighs about 0.98 lb, a bit more than twice as much. A linear foot of 24-inch coil weighs about 0.90 lb in .032 aluminum and 1.95 lb in 24 gauge steel. The full chart and the formula behind it are below.

How each metal is sized

Each roofing metal is ordered a different way, so start with the unit.

Aluminum is ordered by decimal thickness in inches, such as .032 or .040.
Steel is ordered by gauge. A higher gauge number means thinner metal.
Copper is ordered by weight in ounces per square foot under ASTM B370. Its Table 1 gives 16 oz copper a theoretical thickness of 0.0216 inch.
Zinc is ordered in millimeters. RHEINZINK lists standard thicknesses from 0.65 mm to 1.50 mm.

Steel gauge is not an exact thickness. The steel rows below use nominal Manufacturers’ Standard Gauge values for sheet steel. Some roofing suppliers state a minimum instead. Sheffield Metals, for example, puts 24 gauge at a minimum of about 0.023 inch and 26 gauge at about 0.018 inch. When thickness matters, check the mill certificate or the coil tag.

The weight formula

Every weight in this guide comes from one formula:

lb per linear foot = width (in) × thickness (in) × 12 × density (lb/in³)

For weight per square foot, use thickness (in) × 144 × density.

These are the densities used in the chart:

Aluminum: 0.0975 lb/in³, from 2.70 g/cm³.
Steel: 0.2836 lb/in³, from the standard 490 lb per cubic foot.
Copper: 0.323 lb/in³. ASTM B370 bases its table on 0.322, so the results match within half a percent.
Zinc: 0.258 lb/in³, from 7.13 g/cm³ for pure zinc.

Here is a worked example. For 24-inch .032 aluminum, 24 × 0.032 × 12 × 0.0975 = 0.90 lb per linear foot.

These are bare-metal figures. Paint and metallic coatings add a little weight. RHEINZINK lists its titanium zinc at 7.2 g/cm³, which runs about 1% heavier than the pure-zinc figure.

Gauge, thickness and weight chart

Metal and gauge	Inches	mm	lb/sq ft	lb/LF, 20″ coil	lb/LF, 24″ coil
Aluminum .027	0.027	0.69	0.38	0.63	0.76
Aluminum .032	0.032	0.81	0.45	0.75	0.90
Aluminum .040	0.040	1.02	0.56	0.94	1.12
Aluminum .050	0.050	1.27	0.70	1.17	1.40
Steel 22 ga (nominal)	0.0299	0.76	1.22	2.04	2.44
Steel 24 ga (nominal)	0.0239	0.61	0.98	1.63	1.95
Steel 26 ga (nominal)	0.0179	0.45	0.73	1.22	1.46
Steel 29 ga (nominal)	0.0135	0.34	0.55	0.92	1.10
Copper 16 oz	0.0216	0.55	1.00	1.67	2.01
Copper 20 oz	0.0270	0.69	1.26	2.09	2.51
Zinc 0.7 mm	0.0276	0.70	1.02	1.71	2.05
Zinc 0.8 mm	0.0315	0.80	1.17	1.95	2.34

Weights calculated with the formula above. Steel thickness: Manufacturers’ Standard Gauge for sheet steel (Metal Supermarkets for 22 to 26 ga, Makerverse for 29 ga). Copper: ASTM B370 Table 1. Zinc: millimeters converted to inches.

Two notes on the chart. By definition, 20 oz copper weighs 1.25 lb per square foot. The formula lands at 1.26 because 0.323 is slightly higher than the 0.322 that B370 uses. Zinc is often sold in metric widths. RHEINZINK’s standard widths include 500 mm, about 19.7 inches. At that width, 0.7 mm zinc weighs about 1.68 lb per linear foot.

From weight to footage

Flip the formula to find how much coil you have: linear feet = coil weight ÷ lb per linear foot.

1,000 lb of 24-inch .032 aluminum: 1,000 ÷ 0.90 ≈ 1,110 linear feet.
500 lb of 20-inch 24 gauge steel: 500 ÷ 1.63 ≈ 307 linear feet.

Use the coil weight and length calculator for other widths and gauges. Then turn footage into panels with the panels per coil calculator.

Odd widths and flat sheets

For any other width, work from the weight of a one-inch strip. A one-inch strip of .032 aluminum weighs about 0.037 lb per linear foot. The same strip of nominal 24 gauge steel weighs about 0.081 lb. Multiply by the width you need.

Gutter coil is a good example. New Tech Machinery’s MACH II takes 11-3/4 to 12-3/8 inch coil for a 5-inch gutter and 15-inch coil for a 6-inch gutter. In .032 aluminum, 11-3/4 inch coil weighs about 0.44 lb per foot. A 15-inch coil weighs about 0.56 lb per foot.

Flat sheets use the per-square-foot column. A 4 by 10 foot sheet covers 40 square feet. In .032 aluminum it weighs about 18 lb. In nominal 24 gauge steel it weighs about 39 lb.

Picking a gauge for the job

Weight is only one part of the choice. The panel system, the machine and the brake all set limits.

Standing seam steel. Sheffield Metals says 24 gauge Galvalume is usually the standard for standing seam, because most testing and engineering is done at that thickness. It notes that 26 gauge is easier to bend, hem and cut but less rigid.
Roll former limits. New Tech Machinery’s SSQ3 MultiPro runs painted steel from 28 to 22 gauge, painted aluminum from .027 to .040 inch and copper from 16 to 20 oz. Its MACH II gutter machine takes aluminum from .019 to .032 inch.
Brake limits. Van Mark rates its Mark II TrimMaster Pro-Grade for .032 aluminum and 29 gauge painted steel. The Industrial Metal Master 20 is rated for .050 aluminum and 24 gauge painted steel. Compare every model in choosing a Van Mark brake.

Heavier is not always better. Order the gauge the panel engineering calls for, then confirm that your machine and brake can form it.

Gauge traps to avoid

Watch for these three mix-ups.

Different gauge tables

Galvanized steel has its own gauge table with different numbers. Metal Supermarkets lists 24 gauge standard steel at .0239 inch but 24 gauge galvanized at .0276 inch. When a spec says “24 gauge,” find out which table it means.

Aluminum by gauge number

Aluminum also has a gauge scale, and it runs thinner. The same chart puts 24 gauge aluminum at about .020 inch. That is far lighter than .032 roofing aluminum, so always order aluminum by decimal thickness.

Measuring painted coil

Paint adds thickness. Sherwin-Williams lists 0.9 to 1.1 mils on the face of a Fluropon coil and 0.3 to 0.4 mils on the back. That totals roughly .0012 to .0015 inch. So painted .032 aluminum should read close to .033 inch on a micrometer.

Copper has a tolerance too. ASTM B370 allows 16 oz copper to vary by 0.0012 inch either way. That means it can measure from 0.0204 to 0.0228 inch and still conform.

Where to find each metal

Each product page shows the gauge, width and finish options in our catalog:

To see how coil width turns into panel coverage, read coil width and panel coverage. For finish choices, see Kynar PVDF vs. SMP vs. polyester.

Quick answers

Is 24 gauge thicker than 26 gauge?

Yes. A higher gauge number is thinner metal. Nominal 24 gauge is 0.0239 inch and 26 gauge is 0.0179 inch.

What does a 20-foot panel weigh?

Use the coil width, not the coverage. A 20-foot panel rolled from 20-inch, 24 gauge steel weighs about 33 lb. The same panel in .032 aluminum weighs about 15 lb.

What does 16 oz copper mean?

It weighs 16 ounces, or one pound, per square foot. ASTM B370 gives it a theoretical thickness of 0.0216 inch.

Sources

Figures in this guide come from the documents below or are calculated from them. Specs and warranty terms change, so check the current version before you order.

Know the gauge and width? Send the weight or footage you need and we will price it. All coil and sheet is on the coil and sheet page.

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