Free Roof Estimate
Instant roof cost by house size, pitch and material — then compare it with local quotes
Enter your house's length, width and roof pitch and the calculator below gives you the roof area, the squares and materials to order, and a 2026 installed price range for the material you pick. A 40 x 30 ft house with a 6/12 gable roof is about 1,503 sq ft of roof: $6,762–$9,767 in architectural shingles, before tearing off the old roof. No sign-in, no email.
Your roof estimate
House length and width measured on the ground; the overhang and pitch are added for you.
Planning estimate — actual quotes vary
1,503
sq ft of roof
15
squares
50
bundles (+10% waste)
- Synthetic underlayment: 2 rolls
- Drip edge: 18 × 10 ft (156 ft)
- Ridge: 42 ft, 2 cap bundles
- Pitch multiplier: 1.1180
Installed cost, architectural (dimensional) shingles: $6,800 – $9,800Planning range for 2026 ($4.50–$6.50 per sq ft), before tear-off and local price differences. Dimensional shingles cost calculator · Cost by state
Detailed shingle calculatorFull project estimateRoofing calculator
Get quotes from local roofers
Tell local roofing pros about your project and compare their quotes with your planning estimate.
Quote requests are handled by Networx Systems, Inc. and its Partners, who may contact you about your project. We may be compensated for referrals.
🛒 Your materials list
#ad · Amazon- Synthetic underlayment, 1,000 sq ft rolls2 rolls of 1,000 sq ft
- Ice & water shield for the eaves277 sq ft: a 3 ft course along 84 ft of eaves
- Self-stick starter strip156 ft of eaves and rakes
- 1-1/4 in coil roofing nails4,364 nails at 4 per shingle
- Plastic roof cement for flashing1 can for flashing, vents and exposed nail heads
From a local roofing supplier (sold as freight lots on Amazon): shingles 50 bundles (incl. 10% waste) · drip edge 18 × 10 ft pieces · hip & ridge cap 2 bundles for 42 ft
Adds the items above with these quantities to your Amazon cart; you review them there before buying. As an Amazon Associate I earn from qualifying purchases.
Worked examples updated . Every figure below is computed with the same formulas as the calculator.
Roof estimate by house size (2026)
Every row is the calculator above run on a single-storey house with a 6/12 gable roof and a 12-inch overhang. The roof area is the footprint plus overhang times the pitch multiplier (1.1180 at 6/12). Prices are installed planning ranges: 3-tab $3.90–$4.80 and architectural $4.50–$6.50 per sq ft of roof from the site's 2026 roofing cost per square guide, synthetic slate $4.00–$8.00 from This Old House's 2026 slate roof cost guide, and tearing off one layer of asphalt at $100–$175 a square.
| House footprint | Roof area | 3-tab shingles | Architectural shingles | Synthetic slate | Tear-off, 1 layer |
|---|---|---|---|---|---|
| 1,000 sq ft (40 x 25 ft) | 1,268 sq ft · 12.7 sq | $4,945–$6,086 | $5,705–$8,241 | $5,071–$10,143 | $1,268–$2,219 |
| 1,500 sq ft (50 x 30 ft) | 1,860 sq ft · 18.6 sq | $7,256–$8,930 | $8,372–$12,093 | $7,442–$14,883 | $1,860–$3,256 |
| 2,000 sq ft (50 x 40 ft) | 2,442 sq ft · 24.4 sq | $9,523–$11,721 | $10,988–$15,872 | $9,767–$19,534 | $2,442–$4,273 |
| 2,400 sq ft (60 x 40 ft) | 2,911 sq ft · 29.1 sq | $11,354–$13,975 | $13,101–$18,924 | $11,645–$23,291 | $2,911–$5,095 |
| 3,000 sq ft (60 x 50 ft) | 3,605 sq ft · 36 sq | $14,058–$17,302 | $16,220–$23,430 | $14,418–$28,836 | $3,605–$6,308 |
Worked example: a 40 x 30 ft house, 6/12 gable, architectural shingles
- Add the overhang: 42 x 32 ft = 1,344 sq ft under the roof.
- Apply the 6/12 pitch multiplier: 1,344 x 1.1180 = 1,503 sq ft, or 15 squares.
- Price it: 1,503 sq ft x $4.50–$6.50 = $6,762–$9,767 installed.
- Add tearing off one old layer: $1,503–$2,630.
About $8,265–$12,397 all in. Check it against roof cost by state — labour rates move the real number more than materials do.
An online roof estimate vs a roofer's free estimate
The calculator gives you a budget before anyone visits: the size of the roof in squares, the materials it takes and what that usually costs installed. Most roofing contractors will also come out and price the job without charge. You want both, because they answer different questions.
- The online number tells you whether a quote is in the normal range and lets you compare materials before you talk to anyone.
- Only someone on the roof can see soft decking, how many layers are on, failed flashing at chimneys and walls, and whether the attic is ventilated — the things that turn a typical price into your price.
- Measure first, then get quotes: if a contractor's square count is far off yours, ask how they measured. Aerial-measurement reports and a tape on the roof should agree within a few percent.
- Storm damage is different: if hail or wind did it, read the roof insurance claim guide before signing anything, and size the damage with the hail damage calculator.
What a written roof estimate should itemise
- Tear-off and disposal, per layer, and who pays for the dumpster. Price a tear-off with the tear-off cost calculator.
- Underlayment type, and ice barrier at the eaves where the climate calls for it (underlayment calculator).
- New drip edge, starter strip, valley metal and step flashing, not reused.
- Ridge vent or another exhaust, and whether soffit intake is opened up (roof vent calculator).
- Replacement decking priced per sheet as a contingency, rather than a lump sum guessed in advance (roof sheathing calculator).
- The permit fee, and whether it is in the headline number.
- The shingle manufacturer's warranty and the contractor's workmanship warranty, separately and in writing.
How to compare roofing quotes
- Get written estimates from more than one licensed, insured local roofer, all priced against the same scope — the list above is that scope.
- Line them up by squares, material line and tear-off layers before you look at the total. Most of the gap between quotes is what is included, not the labour rate.
- Check the contractor's licence with your state board and ask for proof of liability and workers' compensation insurance.
- Don't pay in cash or the whole price up front: keep the deposit small and tie later payments to finished stages of the work, in a written contract.
- Be careful with door-to-door crews after a storm who ask you to sign quickly or to hand over your insurance claim.
- If the price is a stretch, the roof financing calculator shows the monthly payment on any amount and term.
Free roof estimate FAQ
How much does a new roof cost?
For a 40 x 30 ft single-storey house with a 6/12 gable roof (1,503 sq ft of roof), architectural shingles run about $6,762–$9,767 installed, plus $1,503–$2,630 to tear off one old layer. Bigger, steeper and more cut-up roofs cost more; enter your own measurements above.
How do I get a free roof estimate?
Two ways, and it is worth doing both. Enter your house length, width and pitch in the calculator for an instant budget figure; then ask local roofers to inspect and quote, which most do without charge. The optional quote form under the result sends your project to local roofers through Networx.
Can I estimate my roof without climbing on it?
Yes. Measure the house on the ground, add the overhang on each side, and read the pitch from the attic: hold a level against a rafter and measure the rise over 12 inches of run. The calculator applies the pitch multiplier for you.
Do I have to give my details to get an estimate here?
No. The calculator runs in your browser and nothing you enter in it is stored or sent. The quote form is separate and optional: only what you type into it goes to Networx and its partner contractors, who may contact you, and the site may be paid for that referral.
How many roofing quotes should I get?
More than one, from licensed and insured local contractors, each priced against the same written scope — three is a common number. Compare them line by line rather than by the total.
What should a roof estimate include?
Tear-off and disposal per layer, underlayment and ice barrier, new drip edge, starter and flashing, ventilation, a per-sheet price for any replacement decking, the permit fee, and the material and workmanship warranties stated separately.
Why do roofing quotes vary so much?
Mostly scope: how many layers come off, how much decking is replaced, whether flashing and ventilation are redone, and which shingle line is used. Labour rates differ by region too — the state cost pages show how much.
Price one part of the job
Sources
- Smart Roofing Calculator — 2026 roofing cost per square (asphalt bands, tear-off)
- This Old House — How much does a slate roof cost? (2026)
Prices are planning ranges for budgeting, not quotes. Local labour rates, the number of layers coming off, decking repairs and roof complexity set the real price.