Roof Replacement Cost Calculator 2026
Enter your house dimensions and roof pitch to instantly calculate roof area in m² and sq ft, number of roofing squares, and total replacement cost. Choose from 8 materials including asphalt shingles, Colorbond metal, clay tiles and slate.
🏠 Roof Shape & Dimensions
🧱 Material, Insulation & Labor
📊 Your Roof Project Estimate
Cost Breakdown
🏅 Pro Tip: Don't skimp on underlayment
Ice-and-water shield at eaves and valleys, plus felt underlayment on the rest, is your last line of defence against leaks. Budget $5–8/m² ($0.50–0.75/sq ft) for quality underlayment — it's 2–3 % of the job but can prevent thousands in water damage. For steep pitches over 45°, add 10–15 % extra waste allowance for cut pieces at hips and valleys.
Roofing Cost Guide by Material (2026)
Material choice is the biggest driver of both initial cost and long-term value. The table below shows typical installed costs per m² (and sq ft) for the most common roofing materials in North America and Australia.
| Material | Installed (per m²) | Installed (per sq ft) | Lifespan | Best for |
|---|---|---|---|---|
| Asphalt – 3-tab | $20–35/m² | $1.90–$3.25 | 20–30 yrs | Budget-conscious |
| Asphalt – Architectural | $35–65/m² | $3.25–$6.00 | 30–50 yrs | Best value |
| Metal – Standing Seam | $100–165/m² | $9.30–$15.30 | 40–70 yrs | Modern homes |
| Metal – Colorbond (AU) | $60–110/m² | $5.60–$10.20 | 40–60 yrs | Australian standard |
| Concrete Tiles | $75–130/m² | $7.00–$12.10 | 40–50 yrs | Mediterranean style |
| Clay / Terracotta | $100–185/m² | $9.30–$17.20 | 50–100 yrs | Premium look |
| Slate | $170–350/m² | $15.80–$32.50 | 75–150 yrs | Prestige / heritage |
| Wood Shakes | $70–130/m² | $6.50–$12.10 | 20–30 yrs | Rustic / Pacific NW |
Fully installed prices (materials + labor). US figures in USD; AU Colorbond in USD for comparison. Regional and complexity variations apply.
Roof Types: How Shape Affects Cost and Area
Roof shape dramatically affects the amount of material needed, the complexity of the job and therefore the labor cost.
Gable roof
Two sloping sides meeting at a ridge. The most common style in North America. Simple geometry means lower waste (8–10 %) and straightforward installation. Our calculator gives exact rafter length, ridge length and total eave.
Hip roof
All four sides slope down to the eaves. More wind-resistant than gable — important in hurricane and tornado zones. More complex with hip and valley cuts; allow 12–15 % waste and expect 15–25 % higher labor.
Shed / mono-pitch
A single sloping surface, common on additions, garages and modern architecture. Very simple — lowest waste (5–8 %) and labor. Check local codes for minimum pitch.
Flat / low-slope
Technically not flat — requires at least 1–2 % fall for drainage. Requires different materials: TPO membrane, EPDM rubber or modified bitumen. Not covered in this calculator (different unit economics).
Understanding Roofing Squares
In the US and Canada, roofing material is sold and quoted by the “square” — a unit equal to 100 square feet (9.29 m²). A typical 200 m² roof area requires about 21.5 squares. Bundles of asphalt shingles typically contain 3 bundles per square (±1 depending on product).
Quick conversion guide
Waste Allowance: How Much Extra to Order
| Roof complexity | Recommended waste | Reason |
|---|---|---|
| Simple gable, no hips | 8–10 % | Minimal cuts at ridge and rakes |
| Hip roof, 1–2 valleys | 12–15 % | Diagonal cuts at hips and valleys |
| Complex multi-gable / dormers | 15–20 % | Many short cuts, high scrap rate |
| Slate / clay tiles | 15–20 % | Fragile material, high breakage |
| Corrugated metal sheets | 5–8 % | Large panels, fewer cuts |
Example: Gable Roof 12 × 10 m, 30° Pitch, Architectural Shingles
Single-storey home, 30° pitch (6.9/12), 0.5 m overhang, 10% waste, labor included at $40/m²
| Rafter length | 6.4 m (21 ft) |
| Roof area (net) | 163 m² / 1,754 sq ft |
| Area incl. 10 % waste | 179 m² / 19.3 squares |
| Material (arch. shingles) | $6,800 |
| Underlayment | $815 |
| Labor | $6,520 |
| Total estimate | ~$14,100 |
Frequently Asked Questions
How much does a roof replacement cost in the US?↓
The average roof replacement costs $8,000–$25,000 for a typical single-family home (150–250 m² / 1,600–2,700 sq ft), depending on material and pitch. Asphalt shingles are cheapest at $4–7/sq ft installed; metal roofing runs $10–18/sq ft; slate $20–35/sq ft. Labor typically accounts for 40–60 % of total cost.
How much does a roof replacement cost in Australia?↓
Colorbond metal roofing — the most popular choice — costs AUD $70–120/m² installed. Concrete tiles run AUD $70–110/m², clay tiles AUD $90–140/m². For a 200 m² roof, expect AUD $14,000–$28,000 installed. Sydney and Melbourne prices trend higher due to labor costs.
How do I calculate how many squares of shingles I need?↓
One roofing square = 100 sq ft = 9.29 m². Measure the roof slope area (not the floor area), add 10–15% for waste, then divide by 9.29 m². Our calculator does this automatically — just enter house dimensions and pitch angle. Always order at least 10% extra for waste and damage.
What is the difference between a 4/12 pitch and a 30° pitch?↓
In the US, roof pitch is expressed as rise over run for 12 inches of horizontal distance. A 4/12 pitch rises 4 inches per foot of run, which equals about 18°. A 30° pitch equals a 6.9/12 slope. Our calculator uses degrees (°), which is the global standard — enter your slope angle and we show the US pitch equivalent.
What is the best roofing material for longevity?↓
Slate lasts 75–150+ years but costs $20–35/sq ft installed. Clay tiles last 50–100 years at $12–20/sq ft. Metal (standing seam) lasts 40–70 years at $10–18/sq ft. Architectural asphalt shingles last 30–50 years at $4–7/sq ft — the best value for most budgets. Colorbond steel (AU) typically lasts 40–60 years.
Should I repair or replace my roof?↓
If damage covers more than 30% of the roof, or the roof is over 20 years old (asphalt) or 50 years (tile), replacement usually makes more sense economically. A repair on an old roof often lasts only 3–7 years before the next failure. Get at least 3 written quotes — costs vary significantly by contractor.
How long does a roof replacement take?↓
Most residential re-roofs take 1–3 days. A simple asphalt shingle replacement on a 200 m² (2,150 sq ft) gable roof takes a crew of 3–4 about 1 day. Hip roofs and complex shapes with skylights, valleys or multiple penetrations take longer. Tear-off and decking inspection adds half a day.
What is included in the labor rate?↓
Standard labor rates of $30–55/m² ($3–5/sq ft) typically include: tear-off of existing materials, inspection and repair of decking, installation of underlayment, installation of new roofing material, flashing at penetrations, ridge cap, and site cleanup. Steep-slope surcharges (> 40°) add 20–40%. Always confirm what is included in writing.