Metal Roof Calculator
Calculate the exact number of metal roofing panels, linear feet of trim, and fasteners needed for standing seam, corrugated, or R-panel metal roofing.
Roof Dimensions
sq ft
Panel Specifications
ft
%
Panels Needed
72 panels
Coverage/Panel30.7 sq ft
Eff. Panel Width23.0"
Area w/ Waste2,200 sq ft
Fasteners1,100
Trim & Accessories
Standing Seam panels (24" × 16')72 panels
Ridge cap sections (10 ft)4 pcs
Eave trim sections (10 ft)9 pcs
Rake trim sections (10 ft)9 pcs
Concealed clips/fasteners1,100 pcs
Cost Estimate
Material (22.0 sq @ $800/sq)$17,600
Labor estimate$10,560
Trim & accessories$550
Total Estimated Cost$28,710
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How to Use This Calculator
Select your metal roofing system type, then enter your roof dimensions:
- Roof Length — The measurement from ridge to eave (slope length, not the horizontal run). If you know your horizontal run and pitch, use our Rafter Calculator to find the slope length.
- Roof Width — The length of the roof along the ridge (eave to eave if gable, or ridge length for hip)
- Panel Coverage Width — The net width each panel covers after overlapping (typically 12, 16, or 18 inches for standing seam; 26 or 36 inches for corrugated)
- Panel Length — Cut length of each panel (or leave blank for full slope-length panels)
The calculator outputs panel count, linear footage of trim (ridge cap, eave drip, rake trim, valley flashing), and an estimated fastener count.
The Formula
Panels per Row = Roof Width ÷ Panel Net Coverage Width
Rows = Roof Length ÷ Panel Length
Total Panels = Panels per Row × Rows (rounded up)
With Waste = Total Panels × 1.10
Ridge Cap (linear ft) = Ridge Length
Eave Drip (linear ft) = Eave Length × 2 (both sides)
Rake Trim (linear ft) = Rake Length × 2
Screws (exposed fastener) = Roof Area (sq ft) × 0.8 to 1.2
Rows = Roof Length ÷ Panel Length
Total Panels = Panels per Row × Rows (rounded up)
With Waste = Total Panels × 1.10
Ridge Cap (linear ft) = Ridge Length
Eave Drip (linear ft) = Eave Length × 2 (both sides)
Rake Trim (linear ft) = Rake Length × 2
Screws (exposed fastener) = Roof Area (sq ft) × 0.8 to 1.2
Example: 30 x 24 ft Barn Roof — Corrugated Metal
Example: Simple Gable Barn, Corrugated 26-inch panels, 6/12 pitch
Footprint Width30 ft (15 ft each side)
Slope Length16.8 ft (6/12 pitch)
Ridge Length24 ft
Panel Coverage24 inches net (2 ft)
Panels per Side24 ft / 2 ft = 12 panels
Both Sides24 panels
With 10% Waste27 panels (order 28)
Ridge Cap24 linear ft
Eave Drip48 linear ft
Rake Trim~68 linear ft (both gable ends)
28 full-length panels cut at 16.8 ft each. Order 50 ft of ridge cap and 120 ft of assorted trim to be safe.
Frequently Asked Questions
Standing seam has concealed fasteners with raised seams joining panels — premium look, longest lifespan (40–70 years), and best for very low pitches. Corrugated metal uses exposed screws through the panel surface — lower cost, easier DIY installation, 25–40 year lifespan.
Steel roofing lasts 40–70 years with proper maintenance. Aluminum lasts similarly. Copper and zinc can last 100+ years. Compare this to asphalt shingles at 20–30 years. The higher upfront cost of metal is often justified by its longevity.
In many cases yes, but check local building codes first — most jurisdictions limit roofs to two layers of roofing material. Metal installed over shingles needs furring strips or a suitable substrate to ensure proper ventilation and prevent trapped moisture.
Yes. Metal roofing requires coordinated trim pieces: eave drip edge (starter trim), rake trim for gable ends, ridge cap, valley flashing, and sometimes peak caps and gable trim. Most panel manufacturers offer matching trim in the same color and gauge as the panels.
For residential roofing, 24-gauge steel is the premium standard; 26-gauge is common and cost-effective. Agricultural/commercial buildings often use 29-gauge. Lower gauge numbers mean thicker, stronger steel. Avoid 29-gauge for residential use in snow-heavy or hail-prone areas.