The unit: one roofing square = 100 square feet
Roofing is estimated in SQUARES. One roofing square equals 100 square feet of roof surface. A 30-square roof is 3,000 square feet of roof surface — not 3,000 square feet of floor footprint. A 2,000 sq ft house with a steep 8/12 pitch might have 3,000+ square feet of actual roof because of slope.
Three ways to measure: walk the roof with a tape (most accurate, slowest, and requires being on the roof), satellite measurement reports from EagleView or Hover ($25–$60 per report, accurate within 1-2%), or rough estimates off Google Earth (free, inaccurate). For anything over $5,000, get the satellite report — the $40 cost protects you from a measurement error that wipes out your margin on a single job.
Materials cost per square (2026 ranges)
Per-square material cost for a standard asphalt shingle reroof: • Shingles: $85–$130 (architectural), $60–$90 (3-tab) • Underlayment: $12–$22 • Starter strip: $8–$12 • Ridge cap: $18–$28 • Nails: $5–$8 • Miscellaneous flashing and sealant: $8–$15 Total per-square materials: roughly $95–$135 for asphalt, not counting waste.
Per-job line items that DON'T scale by square: • Drip edge by linear foot • Ice and water shield in valleys and at eaves (required by code in cold states) • Pipe boots ($12–$25 each) • Step flashing for wall-to-roof intersections • Ridge vent if installing • Deck repair (rot replacement, usually a per-sheet add — $80–$150 installed)
Other roofing systems: • Standing seam metal: $300–$700/square installed materials • Modified bitumen: $180–$280/square • TPO: $120–$200/square • Cedar shake: $400–$700/square Add a waste factor of 10% on simple roofs, 15% on cut-up roofs with valleys, 20%+ on steep or very complex roofs.
Labor cost per square
Typical sub-crew rates for tear-off and reinstall on asphalt shingles run $80–$150 per square depending on pitch, complexity, and region. In-house W-2 crews on hourly wages cost about the same per square once you load them with workers' compensation (NCCI 5551 runs $15–$40 per $100 of payroll depending on state), payroll taxes, and benefits.
For estimating, the reliable approach is: total labor cost = squares × your fully-loaded labor rate per square. Track your actual labor cost per square over your last 10 jobs and use the average, not your best one. If your average is $110 per square and you've started bidding $90 because you watched a video on YouTube, you're losing $20 per square on every job and you don't know it yet.
Add separate labor line items for tear-off (if it's not in your reinstall rate), deck repair, and any specialty work like skylight resets, chimney flashing rebuilds, or unusual wall-to-roof transitions.
Overhead — every job has to pay its share
Overhead is everything that isn't direct materials or direct labor: insurance (general liability, workers' comp, commercial auto, tools and equipment), fuel, truck payments, office rent, software subscriptions, sales commissions, advertising, accounting, and the owner's salary. For most roofing companies, overhead runs between 15% and 25% of revenue.
If you don't know your number, calculate it from your most recent full year of P&L: total operating expenses (everything except direct material and direct labor cost of jobs) ÷ total revenue = overhead percentage.
On every job, you must recover your overhead percentage in addition to materials and labor. If your overhead is 20%, every job needs to charge 20% above its direct cost just to cover the company's existence — before any profit.
The markup vs margin mistake that costs $1,000 per job
This is where most roofing contractors lose money without knowing it. There is a structural difference between MARKUP and MARGIN, and using markup math when you mean margin will under-charge you on every single job.
MARGIN is profit as a percentage of SELLING PRICE. A 20% margin on a $10,000 job = $2,000 profit / $8,000 cost. To calculate selling price from cost at a target margin, DIVIDE cost by (1 − margin). Cost of $8,000 ÷ (1 − 0.20) = $10,000.
MARKUP is profit as a percentage of COST. A 20% markup on $8,000 of cost = $1,600 profit + $9,600 selling price — only a 16.7% margin. Adding 20% to your costs and calling it a 20% margin means you're actually working at 16.7% margin.
For a target net profit of 15–25% on roofing work, the divide-by formula is the only one that gets you there. Cost ÷ (1 − target margin) = selling price.
A worked example — 30-square asphalt reroof
30-square asphalt shingle reroof, 6/12 pitch, residential, single-layer tear-off: • Materials: 30 × $115 = $3,450 + $400 in flashing, drip edge, pipe boots = $3,850 • Labor (sub rate $110/sq reinstall + $20/sq tear-off): 30 × $130 = $3,900 • Dump fee: $300 • Permit: $150 • Direct cost subtotal: $8,200 • Overhead at 20%: $8,200 ÷ 0.80 = $10,250 • Profit margin at 20%: $10,250 ÷ 0.80 = $12,813 • Final price: $12,800 (or $12,995 with a clean retail number)
On an insurance-paid job, the carrier will price the same scope using Xactimate. Their pricing may come in higher or lower than yours depending on the line items and their regional rates. If their scope is materially below yours, that's where supplements and scope-of-loss disputes come in — and where having a roofing-focused insurance shop on your side matters.