Corrugated Metal Roof Calculator

Calculate the exact number of corrugated metal panels, screws, ridge cap, and trim pieces for your roof

Quick panel count from roof area and coverage width

Quick presets

sq ft

Panels Needed

98 panels

1,897 sq ft • 19.0 squares

Estimated Cost Range

$15,178 – $30,355

PRO

Professional Calculator

Complete metal roofing material list with panels, trim, and fasteners

sq ft

Estimated Materials

60 bundles

Roof Area

1,792 sq ft

Squares

17.9

Detailed Breakdown

Roof Area1,792 sq ft
With Waste1,971 sq ft
Roofing Squares17.9
Bundles60
How to Use This Calculator
The Corrugated Metal Roof Calculator helps you order the exact panels, screws, ridge cap, and trim for a corrugated steel or Galvalume roof installation.

Panel Count tab: Enter your total roof area, select panel length and coverage width, and add a waste factor. The calculator divides your area by the per-panel coverage to return the total panels needed. This is the fastest way to get a panel count for quoting.

Complete System tab: Enter your roof area plus ridge length, rake length, and eave length. The calculator returns a full bill of materials: panels, screws (with EPDM washers), ridge cap pieces, foam closure strips, rake trim, and eave drip edge. Use this tab when placing a complete supply-house order.

Cost Estimate tab: Select your panel material — galvanized, Galvalume, painted 29-gauge, or painted 26-gauge — and your state. The calculator outputs material cost, labor cost, and total installed cost based on 2026 regional pricing. Compare options side by side to find the best value for your project.

The Formula
The corrugated metal roof calculation uses these formulas:

Coverage Area per Panel = Panel Length × (Coverage Width / 12) For a 12 ft panel with 26" coverage: 12 × (26 / 12) = 26 sq ft per panel

Panels Needed = (Roof Area × (1 + Waste%)) / Coverage Area per Panel For 1,800 sq ft with 10% waste: (1,800 × 1.10) / 26 = 76.15 -> 77 panels

Screws Needed = (Roof Area / 100) × 80 screws per square For 1,800 sq ft: 18 × 80 = 1,440 screws

Ridge Cap Pieces = Ridge Length / 3 ft effective (with 6" overlap from 3.5 ft pieces) For 40 ft ridge: 40 / 3 = 13.3 -> 14 ridge cap pieces

Rake Trim = Total Rake Length / 10 ft effective per piece (10.5 ft pieces, 6" overlap) For 56 ft: 56 / 10 = 5.6 -> 6 rake trim pieces

Material Cost = Panels × Panel Cost + Screws × $0.08 + Ridge Cap × $18 + Trim × $14 Labor Cost = Roof Area × Labor Rate per sq ft ($3.50-6.00 depending on region)
Example Calculation
Example: Average Home in Texas

David is installing a corrugated metal roof on his 1,800 sq ft ranch-style home in San Antonio. The roof is a simple gable, 40 ft long, with 14 ft rafter runs on each side. He chooses Galvalume 29-gauge panels.

Step 1: Calculate panels needed Panel: 12 ft long × 26" coverage width = 26 sq ft per panel Panels: (1,800 × 1.10) / 26 = 76.15 -> 77 panels

Step 2: Calculate screws Screws: (1,800 / 100) × 80 = 1,440 screws Buy: 2 boxes of 750 (#10 × 1.5" hex-head with EPDM washer)

Step 3: Calculate trim and accessories Ridge cap: 40 ft / 3 ft effective = 14 pieces Foam closure strips: 40 ft ridge × 2 sides = 80 ft -> 27 strips (3 ft each) Rake trim: 56 ft / 10 ft = 6 pieces Eave drip edge: 80 ft / 10 ft = 8 pieces

Step 4: Estimate cost
• 77 Galvalume panels (12 ft): 77 × $32 = $2,464
• Screws (2 boxes): 2 × $65 = $130
• Ridge cap (14 pcs): 14 × $18 = $252
• Foam closures (27 pcs): 27 × $4 = $108
• Rake trim (6 pcs): 6 × $14 = $84
• Eave drip (8 pcs): 8 × $12 = $96
• Materials total: ~$3,134
• Labor: 1,800 × $4.50 = $8,100
• Total installed: ~$11,234 ($6.24/sq ft)

Frequently Asked Questions

How many corrugated metal panels do I need?
Divide your total roof area by the coverage area of one panel. A standard corrugated panel covers 26 inches wide. For a 12-foot panel that is 26 ft² per panel (12 × 26/12 = 26 sq ft). For a 1,800 sq ft roof: 1,800 / 26 = 69.2 panels, plus 10% waste = 77 panels. Always round up and add waste because panels cannot be spliced width-wise.
How many screws per corrugated metal panel?
Plan for 80 screws per 100 square feet (roofing square). For field panels, place screws every 24 inches in each valley at purlins spaced 24 inches apart. Eave and ridge rows get a screw in every valley. A typical 12-foot × 26-inch panel needs about 20-22 screws. For 1,800 sq ft you need approximately 1,440 screws. Buy a box of 1,500 (#10 × 1.5" hex-head with EPDM washer) to be safe.
What is the difference between galvanized, Galvalume, and painted metal roofing?
Galvanized steel is coated with zinc and is the cheapest option ($1.50-2.25/sq ft in 2026) but typically lasts 20-30 years. Galvalume is coated with 55% aluminum and 45% zinc, resists corrosion better, and lasts 40-60 years ($2.00-3.00/sq ft). Painted Galvalume adds a baked-on acrylic or PVDF (Kynar) finish for color and UV protection ($2.50-5.00/sq ft). For a primary residence, Galvalume or painted Galvalume is the best value.
Can I install corrugated metal roofing over existing shingles?
Yes, in many jurisdictions you can install corrugated metal over one layer of existing asphalt shingles by adding furring strips (1×4 or 2×4 purlins) over the shingles. This creates an air gap, allows drainage, and saves tear-off cost ($1,000-3,000). However, check your local building code — some areas require full tear-off, and adding weight to an already-loaded roof may require an engineering review. Most manufacturers require purlins for warranty.
How long does a corrugated metal roof last?
A 29-gauge Galvalume corrugated roof lasts 40-60 years with minimal maintenance. A painted Galvalume (Kynar/PVDF finish) can last 50-70 years. By comparison, architectural asphalt shingles last 25-30 years. The upfront cost of metal is 2-3 times higher, but the lifecycle cost is often lower because you avoid one or two re-roofs. Most metal roofing carries a 40-year manufacturer warranty.

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