Metal Panel Calculator

Calculate exposed-fastener metal roofing panel quantity, ridge cap, gable trim, eave trim, foam closures, and screw count by roof area, panel width, overlap, and gauge for agricultural, commercial, and residential buildings

Calculate the number of metal panels needed based on roof dimensions and panel size

Quick presets

sq ft

Panels Needed

69 panels

2,166 sq ft • 21.7 squares

Estimated Cost Range

$17,328 – $34,656

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 Metal Panel Calculator helps you estimate the number of exposed-fastener metal roofing panels, trim pieces, foam closures, and screws for agricultural, commercial, and residential buildings. Unlike the Standing Seam Calculator (which covers concealed-fastener snap-lock and mechanical seam panels) or the Corrugated Metal Calculator (which focuses on traditional corrugated wavey sheets), this tool covers the most popular exposed-fastener profiles: R-panel, PBR (purlin-bearing rib), AG panel, and 5V-crimp.

Panels tab: Enter your total roof area and select the panel coverage width — 26 inches is the most common for R-panel and PBR profiles, while 36 inches covers 5V-crimp and some wide corrugated profiles. Choose the panel length that matches your rafter length (eave to ridge) to avoid horizontal lap joints. If no standard length matches, select the next longer size or choose custom cut-to-length. The calculator divides the total roof area by the net panel coverage, adds waste, and determines the number of panels. The roof pitch affects the total slope area if you entered the horizontal footprint.

Trim & Closures tab: Enter the linear footage for ridge, gable/rake, eave, and valley trim. Each trim type is sold in 10-foot sections with 6-inch overlap at joints. The calculator determines the number of sections for each trim type. Foam closures seal the profiled gaps at the ridge and eave — select both inside and outside closures for complete weather protection. The calculator determines the closure count based on the number of panels at each location.

Cost Estimate tab: Select the panel gauge (29ga standard or 26ga heavy-duty) and color/finish (galvalume, painted SMP, or Kynar). The calculator prices panels, trim, closures, and screws separately, then adds installation labor if professional install is selected. DIY installation of exposed-fastener panels is feasible for experienced builders with basic tools — a screw gun, tin snips, and a tape measure. The state selector adjusts labor rates for your region.

The Formula
The metal panel calculator uses these formulas:

Panel Count Net coverage per panel = Panel Width (inches) / 12 x Panel Length (ft) = sq ft per panel Panels needed = ceil(Roof Area x Pitch Factor x (1 + Waste%) / Net Coverage per Panel) Pitch factors: 1/12-3/12 = 1.00-1.03, 4/12-6/12 = 1.05-1.12, 7/12-9/12 = 1.16-1.25, 10/12-12/12 = 1.30-1.41

Trim Sections (10 ft each, 6" overlap) Ridge cap sections = ceil(Ridge Length x 1.05 / 9.5) Gable trim sections = ceil(Gable Length x 1.05 / 9.5) Eave trim sections = ceil(Eave Length x 1.05 / 9.5) Valley trim sections = ceil(Valley Length x 1.05 / 9.5)

Foam Closures Inside closures (ridge) = Number of panels at ridge line Outside closures (eave) = Number of panels at eave line Panels at ridge = ceil(Ridge Length x 12 / Panel Width) Panels at eave = ceil(Eave Length x 12 / Panel Width)

Screws Panel screws = Panels x Ribs per Panel x (Panel Length / Purlin Spacing) Side lap screws = Panels x (Panel Length / 2 ft spacing) Trim screws = Total Trim LF x 2 screws/ft Total screws with 10% extra = (Panel + Side Lap + Trim) x 1.10 Screw boxes = ceil(Total Screws / 500)

Material Cost Panels: Count x Panel Length x Panel Width/12 x Price per sq ft Ridge cap: Sections x $8-$15 per LF x 10 ft Gable trim: Sections x $5-$10 per LF x 10 ft Eave trim: Sections x $3-$6 per LF x 10 ft Closures: Count x $2-$4 each Screws: Boxes x $25-$40 each

Labor Cost Professional: Roof Area x $2-$5/sq ft State multiplier applied to labor

Total Cost Total = Panels + Trim + Closures + Screws + Labor
Example Calculation
Example: Residential Gable Roof — 2,000 sq ft, 26" R-Panel, 29ga Painted, Professional Install

Dave is roofing a 40-foot long ranch-style home with a simple gable roof. Each slope is 25 feet (eave to ridge) and 40 feet long, totaling 2,000 square feet. He chooses 29 gauge painted R-panel in Burnished Slate with 12-foot panels.

Step 1: Panel Count
• Roof area: 2,000 sq ft (already measured on slope)
• Panel coverage: 26" / 12 x 12 ft = 26 sq ft per panel
• Panels needed: 2,000 / 26 = 76.9 → 77 panels
• With 10% waste: 77 x 1.10 = 84.7 → 85 panels

Step 2: Trim Sections
• Ridge: 40 ft → ceil(40 x 1.05 / 9.5) = ceil(4.42) = 5 ridge cap sections
• Gable trim: 4 rakes x 25 ft = 100 LF → ceil(100 x 1.05 / 9.5) = ceil(11.05) = 12 gable sections (note: actual spec had 60 LF for 2 gable ends)
• Using the scenario 60 LF gable: ceil(60 x 1.05 / 9.5) = ceil(6.63) = 7 gable sections
• Eave trim: 2 x 40 ft = 80 LF → ceil(80 x 1.05 / 9.5) = ceil(8.84) = 9 eave sections

Step 3: Foam Closures
• Panels at ridge: ceil(40 x 12 / 26) = ceil(18.5) = 19 per side x 2 sides = 38 inside closures
• Panels at eave: ceil(80 x 12 / 26) = ceil(36.9) = 37 outside closures
• Total closures: 75 at $3 each = $225

Step 4: Screws
• Panel screws: 85 panels x 5 ribs x 6 purlin lines = 2,550
• Side lap screws: 85 x 6 = 510
• Trim screws: (40 + 60 + 80) x 2 = 360
• Total: 3,420 x 1.10 = 3,762 screws → 8 boxes of 500 = $240

Step 5: Material Cost
• 85 panels x 26 sq ft x $4.50/sq ft (29ga painted): $9,945
• Ridge cap: 5 x 10 ft x $10/LF = $500
• Gable trim: 7 x 10 ft x $7/LF = $490
• Eave trim: 9 x 10 ft x $4.50/LF = $405
• Closures: $225
• Screws: $240
• Materials subtotal: $11,805

Step 6: Labor
• Professional install: 2,000 sq ft x $3.50/LF = $7,000
• US average multiplier: 1.00
• Labor subtotal: $7,000

Step 7: Total
• Materials: $11,805
• Labor: $7,000
• Total: $18,805

Summary: 85 panels of 29ga painted R-panel (26" x 12 ft), 5 ridge cap sections, 7 gable trim sections, 9 eave sections, 75 foam closures, and 8 boxes of screws, professionally installed on a 2,000 sq ft gable roof: approximately $18,800. At $9.40 per square foot installed, this is a cost-effective metal roof option that should last 30-40 years with periodic fastener inspection and replacement.

Frequently Asked Questions

How many metal panels do I need for my roof?
Divide your total roof area by the net coverage area per panel. For example, a 26-inch wide panel that is 12 feet long covers 26/12 x 12 = 26 square feet per panel. For a 2,000 square foot roof: 2,000 / 26 = 77 panels. Add your waste factor (10% for simple gable, 15% for hips and valleys) to get the order quantity: 77 x 1.10 = 85 panels. If the panel length matches your rafter length, you need only one row of panels with no horizontal laps. If the slope is longer than the panel, you will need additional panels for the second course with 6-12 inches of horizontal overlap, which increases the total count. Always round up to the next whole panel because you cannot buy partial panels.
What is the difference between 29 gauge and 26 gauge metal panels?
29 gauge metal panels are 0.014 inches thick and are the most common choice for residential and agricultural buildings. They are lighter, less expensive (typically $3-$6 per square foot), and adequate for roofs with 24-inch purlin spacing and moderate snow loads. 26 gauge panels are 0.018 inches thick — roughly 30% thicker and noticeably stiffer. They resist denting better, span wider purlin spacing (up to 36 inches), and handle heavier snow loads. 26 gauge panels cost $4-$8 per square foot but offer a longer service life and better appearance because the thicker metal is less prone to oil-canning (visible waviness in flat areas). For permanent residential roofs, 26 gauge is the better long-term investment. For agricultural buildings, shops, and budget projects, 29 gauge is perfectly adequate.
What foam closures do I need and how many?
Foam closures are profile-matched strips that seal the gaps in the corrugated panel shape at the ridge and eave. You need one inside closure per panel at the ridge (flat side up, profiled side against the panel) and one outside closure per panel at the eave (profiled side up, flat side against the trim). Each closure strip is typically 3 feet long and covers one 26-inch or 36-inch panel width. For a roof with 85 panels, you need approximately 85 inside closures for the ridge and 85 outside closures for the eave, totaling 170 closure strips. Closures cost $2-$4 each, so the total is $340-$680 for a typical residential roof. Closures must match your specific panel profile — R-panel closures do not fit corrugated panels and vice versa. Order closures from the same supplier as the panels to ensure profile compatibility.
How many screws do I need for metal panel roofing?
The standard fastener pattern for exposed-fastener metal panels is one screw per rib (every 6-9 inches across the panel width) at each purlin or deck attachment line. For a 26-inch wide panel with 5 ribs and purlins at 24 inches on center, each panel on a 12-foot slope crosses 6 purlin lines, requiring approximately 30 screws per panel. For 85 panels, that is 2,550 screws for panel-to-purlin attachment. Side lap stitching screws (connecting adjacent panels at the overlap) add approximately 6 screws per panel at 24-inch spacing along the 12-foot length, totaling another 510 screws. Total: approximately 3,060 screws for an 85-panel roof. Screws are sold in boxes of 250 or bags of 500, so you would need approximately 7 boxes of 500. At $25-$40 per box, fastener cost is $175-$280 total. Always buy 10% extra for dropped or damaged screws.
Can I install exposed-fastener metal panels over existing shingles?
Installing metal panels over existing asphalt shingles is possible and commonly done, but it requires furring strips (purlins) installed horizontally over the shingles to create a flat, even nailing surface. The typical method is to install 1x4 or 2x4 furring strips at 24 inches on center perpendicular to the panel direction, screwed through the shingles into the rafters. The metal panels are then screwed to the furring strips. This method avoids the cost and mess of shingle tear-off ($1-$2 per square foot saved) and adds a ventilation air space between the shingles and the metal. However, it adds the cost of furring strips and installation ($0.50-$1.50 per square foot). Local building codes may limit the number of roof layers to two, so if there are already two layers of shingles, tear-off is required. The added weight of metal panels over shingles is minimal (about 1.5 lbs per square foot) and well within structural limits for most roofs.

Related Calculators

Standing Seam Calculator

Calculate standing seam metal roofing panels and clips

Corrugated Metal Calculator

Estimate corrugated roofing sheets and fasteners

Metal Roof Cost Calculator

Compare metal roofing costs by material and system type

Roofing Screw Calculator

Calculate exact screw counts for metal roofing panels

Purlin Calculator

Determine purlin size, spacing, and quantity for metal roofs

Related Guides & Resources

Metal vs Shingles Tile Roof Guide Slate Roof Guide