Understanding your result
The headline is the installed cost range, with the per-square range beneath it. The stats show materials, labor and the per-square-foot figure; the bars compare the low and high estimates. The breakdown builds each line: the per-square material and labor ranges with their multipliers, the tear-off, the underlayment, the permit, the totals, and the cost per square and per square foot.
The number to compare with a quote is the per square figure, which is how roofers price. If a quote lands outside the range, the breakdown says where: a labor line far above the high end on a walkable roof, or a materials line that implies a gauge or a finish you did not ask for. The roof replacement cost calculator runs the same arithmetic for asphalt, tile and slate for a like-for-like comparison, and the tear-off calculator prices the dumpster that the tear-off line assumes.
The quantities behind the materials line are in the panel calculator and the standing seam calculator; with a supplier’s price per panel you can replace the survey figure with your own under “my own prices”.
How we calculate this
Each of the low and high totals is built from the low or high end of the survey range, so the two ends are internally consistent: the low total is a plain, walkable, low-cost-region roof in a basic panel; the high total is the opposite. The 12 percent on materials is the trim, closures, tape and screws as a share of panel cost, which is what the trim and screws calculators add up to on a typical roof.
The multipliers are the roofing trade’s rules: steep or cut-up roofs cost 15 percent more labor, very steep ones 30; a second storey adds 5 percent for the extra hoisting and staging; thinner gauge is cheaper and thicker dearer. The what roofers charge per square guide gives the survey sources and their years in full.
The assumptions behind the numbers
| Assumption | Default | Where it comes from |
|---|---|---|
| Exposed fastener, materials and labor | $300–$600 and $300–$600 per square | 2025 published cost surveys (HomeGuide, Fixr, Angi) for ribbed and corrugated metal, split into materials and labor |
| Standing seam | $600–$1,200 and $500–$1,000 per square | The same surveys for standing seam |
| Metal shingles and tiles | $500–$900 and $400–$800 per square | The same surveys for stone-coated and metal shingle products |
| Gauge factor | 0.85 (29 ga), 1.0 (26 ga), 1.2 (24 ga) | Supplier price lists; thinner panels are cheaper per square |
| Pitch and complexity | 1.0 / 1.15 / 1.3 | Roofing estimating practice for walkable, steep and very steep roofs |
| Storeys | 1.05 for two or more | Estimating practice for hoisting and staging |
| Tear-off and disposal | $150 per square per layer | 2025 surveys ($100–$200) |
| Underlayment | $40 per square | High-temperature synthetic underlayment, supplier prices |
| Trim, closures and fasteners | 12% of panel cost | The trim and screws calculators on a typical roof |
| Regional factor | 1.0 | National average; 0.85 to 1.3 by region |
Assumptions last reviewed October 7, 2026.
The calculator does not price skylights, snow guards, gutters, decking repairs found after tear-off, or the premium for a non-standard colour or a Kynar finish, and it does not know local labor rates beyond the regional factor. The standing seam versus exposed fastener guide compares the systems on life and maintenance as well as price.
Two worked examples
An exposed-fastener roof over a tear-off
2,000 square feet (20 squares), ribbed exposed-fastener panels, 26-gauge, walkable, one storey, one layer torn off at $150 per square, $40 underlayment, $300 permit, national average region.
- Materials: $300 to $600 × 20 × 1.12 = $6,720 to $13,440
- Labor: $300 to $600 × 20 = $6,000 to $12,000
- Tear-off: $150 × 20 = $3,000; underlayment: $800; permit: $300
- Total: $16,820 to $29,540, $841 to $1,477 per square, $8.41 to $14.77 per square foot
The tear-off is a tenth of the low total. Going over the old shingles, where allowed, takes the low end to about $13,800.
A standing seam roof on a steep two-storey house in a high-cost city
The same 20 squares, standing seam, 24-gauge, steep (7/12 to 9/12), two storeys, no tear-off (over one layer), regional factor 1.2.
- Materials: $600 to $1,200 × 1.2 × 20 × 1.12 = $16,128 to $32,256
- Labor: $500 to $1,000 × 1.15 × 1.05 × 20 × 1.2 = $14,490 to $28,980
- Underlayment: $800; permit: $300
- Total: $31,718 to $62,336, $1,586 to $3,117 per square
Roughly double the exposed-fastener roof: the 24-gauge standing seam panel is twice the material, and the steep two-storey roof in an expensive city makes the labor two and a half times.
Where to find your inputs
Roof area. The sloped area from the roof area calculator, not the floor area. Twenty squares is a modest single-storey house.
Panel type and gauge. From the quote or the product you are considering; 26-gauge exposed fastener and 24-gauge standing seam are the residential norms.
Pitch and storeys. From the pitch calculator and the house; a quote will say whether the roofer priced it as steep.
Tear-off. Whether the old roof comes off and how many layers it has; a roofer can tell from the eave edge.
Region. A judgement: 0.85 for a low-cost rural area, 1.0 average, 1.15 to 1.3 for a high-cost metropolitan area.
Common mistakes
- Comparing per square foot of floor. Roofers price per square of roof. Use the roof area.
- Reading the range as a quote. It is the band quotes fall in. Get three.
- Skipping the tear-off. Where the old roof must come off, it is 10 to 15 percent of the job plus a dumpster.
- Forgetting the trim. Trim, closures and fasteners are a tenth of the material cost and a separate line on the supplier’s invoice.
- Pricing standing seam at exposed-fastener labor. Clips, seams and trim take twice the time.
- Ignoring the deck. Rotten sheathing found after tear-off is extra by the sheet. Keep a contingency.
Questions people ask
- How much does a metal roof cost per square?
- Published 2025 cost surveys put exposed-fastener ribbed or corrugated roofing at roughly $800 to $1,500 per square installed (about $8 to $15 per square foot), standing seam at $1,200 to $2,500 and metal shingles at $1,000 to $1,800, before tear-off. The calculator's default 20-square exposed-fastener roof comes to $16,800 to $29,500 with tear-off, underlayment and permit, $841 to $1,477 per square.
- Is standing seam worth the extra cost?
- It costs roughly 50 to 100 percent more per square than exposed-fastener panels, for concealed fasteners that never need replacing, panels that can float with thermal movement, and a life the surveys put at 50 years or more against 30 to 40. On a roof you will own for decades, or one with a low pitch where exposed screws are a risk, the difference usually pays; on a barn or a shed it usually does not.
- Does gauge change the price much?
- Thinner is cheaper: 29-gauge panels run about 15 percent less than 26-gauge and 24-gauge about 20 percent more, which the calculator applies as a multiplier on materials. Residential roofs are usually 26-gauge for exposed fastener and 24-gauge for standing seam; 29-gauge is agricultural and dents in hail.
- Can a metal roof go over shingles?
- Often, over one layer in sound condition, on battens or a synthetic underlayment, where the local code allows it; that saves the tear-off line, about $100 to $200 per square per layer plus the dumpster. Untick "tear off" to see the difference. Two existing layers, a soft deck or a code that forbids it mean a tear-off.
- What does the regional factor do?
- Labor rates vary by a third or more between regions, and surveys report national averages. The factor scales labor and tear-off: about 0.85 in low-cost rural areas, 1.0 at the national average, 1.15 to 1.3 in high-cost metropolitan areas. Materials are scaled less by region, so the factor does not touch them.
- Why is the range so wide?
- Because it is a range of real installed prices: panel quality, trim complexity, the crew's rates, the roof's cut-up-ness and the region all vary independently. A standing seam roof on a plain gable in a cheap region sits at the bottom of its band; a mechanically seamed roof with hips and dormers in a city sits at the top. Three local quotes narrow it to the real number.