Estimate your metal roof cost with our free calculator. Get panel count, trim lengths, underlayment, fasteners, and total installed price in seconds.
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Metal roofing costs vary wildly. A standing seam panel runs three times the price of corrugated. The pitch changes how much surface area you actually cover. And trim, underlayment, and fasteners can add 30% to the material bill before labor. This calculator handles all of it in one pass. Pick your roof type, enter the building footprint and pitch, and set the panel profile. The tool returns roof surface area, panel count, total panel length, every trim piece, underlayment rolls, and fastener boxes. Add unit costs and you get a total installed estimate plus cost per square foot. Contractors use it for bids. Homeowners use it to sanity-check quotes.
Choose your currency. The symbol changes, but the math stays the same.
Pick a roof type. Gable, hip, shed, gambrel, or direct area entry.
Enter building length and width. For direct entry, skip to total roof surface area.
Set the roof pitch. Use rise:12, degrees, or percent.
Add the overhang. Twelve inches is typical.
Choose a panel preset or enter custom width and length.
Set waste factor, orientation, and gauge.
Toggle trim, underlayment, and fastener details.
Enter unit costs and read the summary.
Roof area drives everything. The tool converts your building footprint to plan area, adds overhangs, then multiplies by a pitch factor.
Formula: Roof Surface Area = Plan Length × Plan Width × √(1 + Pitch²)
Plan length is building length plus two overhangs. Plan width is building width plus two overhangs. Pitch is the rise over 12 (converted to a decimal).
For a gable roof, ridge length equals plan length. Eave length is twice plan length. Rake length covers the four sloped edges. Hip roofs shorten the ridge by the building width. Shed roofs have no ridge and only one eave.
Panel count comes from roof area plus waste, divided by the coverage area of one panel. Trim lengths come from the geometry. Underlayment rolls divide roof area by coverage per roll. Fasteners multiply roof area by a per-square-foot rate.
A 36-foot by 28-foot gable roof at 7:12 pitch. Overhang is 12 inches. Standing seam panels, 16-inch coverage width, 20-foot length. 8% waste. Synthetic underlayment, 1,000 ft² per roll.
Step 1 — Plan dimensions. Length = 36 + 2 = 38 ft. Width = 28 + 2 = 30 ft.
Step 2 — Pitch ratio. 7/12 = 0.5833. Multiplier = √(1 + 0.5833²) = √1.3403 = 1.1577.
Step 3 — Roof area. 38 × 30 × 1.1577 = 1,319.8 ft².
Step 4 — Squares. 1,319.8 / 100 = 13.2 squares.
Step 5 — Panel count. Panel area = 16 in × 20 ft = 1.333 ft × 20 ft = 26.67 ft². With 8% waste: 1,319.8 × 1.08 = 1,425.4 ft². Panels = ceil(1,425.4 / 26.67) = 54 panels.
Step 6 — Total panel length. 54 × 20 = 1,080 ft.
Step 7 — Ridge length. 38 ft. Eave length = 2 × 38 = 76 ft. Rake length = 4 × slope of half-width. Half-width = 15 ft. Slope = √(15² + (15×0.5833)²) = √(225 + 76.6) = √301.6 = 17.37 ft. Rake = 4 × 17.37 = 69.5 ft.
Step 8 — Underlayment rolls. 1,319.8 / 1,000 = 1.32, ceil = 2 rolls.
Step 9 — Fasteners. At 1.5 per ft²: 1,319.8 × 1.5 = 1,980 fasteners. Boxes = ceil(1,980 / 250) = 8 boxes.
Step 10 — Cost. If panels are $3.50/ft², panel cost = 1,425.4 × 3.50 = $4,988.90. Ridge at $6/ft = $228. Eave at $4/ft = $304. Rake at $4.50/ft = $312.75. Underlayment at $120/roll = $240. Fasteners at $45/box = $360. Sealant $80. Material subtotal = $6,513.65. Labor at $2.50/ft² = 1,319.8 × 2.50 = $3,299.50. Total = $9,813.15. Cost per ft² = $7.44. Cost per square = $744.
Material costs $3 to $12 per square foot. Installed costs $6 to $18 per square foot. Standing seam runs the high end. Corrugated and R-panel run the low end. A 1,500 ft² roof typically lands between $9,000 and $27,000 installed.
Multiply building length by width, add overhangs, then multiply by the pitch multiplier. The multiplier is √(1 + pitch²). For a 6:12 pitch, it’s 1.118. A 30×40 building with 12-inch overhangs has a plan area of 1,344 ft², so roof area is 1,502 ft².
Divide roof area with waste by panel coverage area. A 16-inch by 20-foot panel covers 26.67 ft². For a 1,500 ft² roof with 10% waste, you need 1,650 ft² of panels, so 62 panels.
Corrugated galvanized steel. It costs $2 to $4 per square foot for material and $4 to $9 installed. R-panel is similar. Both use exposed fasteners.
40 to 70 years. Standing seam with a quality coating lasts 50+ years. Corrugated lasts 30 to 45 years. Both far outlast asphalt shingles.
Yes. Underlayment provides a secondary water barrier and prevents condensation. Synthetic underlayment is standard. Peel-and-stick is used at eaves and valleys in cold climates.
Standing seam has raised interlocking ribs that hide fasteners. Corrugated is wavy and uses exposed screws. Standing seam is more watertight and lasts longer, but costs more.
8% to 10% for a simple gable. 12% to 15% for a hip roof or one with valleys. Complex roofs need 15% to 20%. Waste covers cuts at hips, valleys, and rake edges.
About 1.5 per square foot for exposed-fastener panels. Standing seam uses concealed clips, about 1 per square foot. High-wind areas need more.
Yes, by 1% to 6% depending on region. Metal roofs also cut cooling costs and may qualify for insurance discounts.
Yes, in many cases. Building codes usually allow it if the existing roof is in good shape. You’ll need purlins or a solid substrate, depending on the panel type. Check local code before planning.
24-gauge is standard for residential standing seam. 26-gauge works for agricultural and shed roofs. 22-gauge is heavy-duty for commercial or high-wind areas.
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