How many squares are in a 2,400 sq ft roof?

A square in roofing is 100 square feet of finished roof surface. 2,400 sq ft = 24 squares of finished area. Once you add waste (typically 10–15% for architectural shingles, more for cut-up hip roofs), you'll be ordering 27–28 squares of material.

What's a fair labor rate per square for a roof tear-off?

In most U.S. markets in 2026, single-layer tear-off on a walkable pitch (4/12–7/12) runs $120–$180 per square of labor, depending on crew productivity and regional wages. Steep pitch (9/12+) pushes labor to $200–$300/sq because of harness requirements and slower production.

Should I include deck replacement in my bid price?

No — always break it out. Quote a reasonable allowance (e.g., first 2 sheets included) with overage billed per-sheet as a change order. Homeowners understand that rotten deck is invisible until tear-off; they do not understand a $3,000 surprise inside a flat price.

How do I handle a roof with multiple layers I didn't see during estimating?

Document it on arrival with photos, stop work, present the change order before tear-off. Two-layer tear-off typically adds $30–$50 per square in labor plus a larger dumpster. If you write your contract well it covers this: 'Existing layers beyond one billed at actual cost per additional square.'

What's the biggest mistake new roofing contractors make when bidding?

Quoting from Google Earth without walking the roof. You'll miss valleys, misread pitch, miss soft deck, and miss the ugly detail shots around chimneys and skylights. A 20-minute roof walk is the single highest-ROI thing you do on a bid.

How to Bid a Roofing Job: Full Walkthrough With Example Numbers

Walk the roof before you quote

Every roofing bid that goes sideways starts with the same mistake: the contractor priced from the ground. You can see three sides of the house from the driveway and miss a 14-foot valley on the back. You can guess the pitch wrong by two points. You can miss the layer of shingles that's already under the existing layer. All three mistakes together kill your margin before the tear-off is done.

A roof walk takes twenty minutes and saves four-digit losses. Bring a tape, a pitch gauge (or a smartphone level app), a moisture meter if you've got one, and a notepad. Sketch the roof plane by plane. Mark every penetration: vents, pipes, skylights, satellite mounts, chimneys. Mark every valley. Count the ridges and hips separately. Note where the gutters will hit flashing. Take photos of soft spots, stained sheathing seen from the attic, and the underside of the decking.

What to measure

Plane dimensions in feet (length × rake-to-eave height along the slope, not horizontal).
Pitch for each plane — a 6/12 and a 12/12 on the same roof can mean two different labor rates.
Ridge, hip, valley, rake, and eave linear footage.
Layers currently on the deck (look at the rake edge and in the attic).
Decking condition — plywood vs. OSB, any sag, stains, soft spots.
Penetrations and obstacles (satellite dishes, solar mounts, chimney crickets).

From measurements to material counts

Roofing is sold by the square — 100 square feet of finished roof. Convert your plane totals to squares and then add waste. For a straightforward gable roof, 10% waste is standard. For a cut-up hip roof with multiple valleys, 15% is safer. If you're doing a steep roof where you'll be trimming a lot of starter strips, 17–18% isn't crazy.

Example: 2,400 sq ft gable roof

Say you measured 2,400 square feet of roof surface across all planes, it's a 7/12 gable with two simple valleys, and you're quoting architectural shingles.

Squares: 2,400 ÷ 100 = 24 squares
With 12% waste: 24 × 1.12 = 27 squares of shingles
Underlayment (30 lb felt or synthetic): 27 squares
Ice & water shield: 2 rolls (eaves + valleys on a house this size, verify code in your jurisdiction)
Ridge cap: linear feet of ridge + hips, typically sold per bundle covering ~25 LF
Drip edge: linear feet of eaves + rakes
Starter strip: linear feet of eaves
Nails: ~2 lbs per square (4-nail pattern on 6/12, 6-nail on steep or high-wind)
Pipe boots, step flashing, counter flashing as needed

Labor: where every bid actually lives or dies

Material costs are public. Your supplier quotes the same shingle to every contractor within 3%. What makes a bid profitable or disastrous is the labor line. Price labor as a per-square rate that reflects difficulty, not a single average.

Rough labor rates (U.S., 2026)

Conditions	Typical labor $/sq
Single layer tear-off, walkable pitch (4/12–7/12), gable	$120–$180
Two-layer tear-off, same pitch	$150–$220
Steep pitch (9/12+), harness required	$200–$300
Cut-up hip/dormer roof with many valleys	$180–$260
Two-story with tricky staging (conservatory, pool, hedges)	Add $20–$50/sq

These assume a 4-person crew, reasonable supplier proximity, and no deck replacement. They are rough. Your market can be 20% higher or lower — the spread tells you what categories of difficulty are worth to price.

Deck replacement

Never bury deck repair inside your square price. Quote a per-sheet allowance (e.g., “$85 per sheet of 7/16 OSB installed, first 2 sheets included”) with the overage billed as a change order. Homeowners understand “we won't know until the shingles are off.” They don't understand a $3,000 surprise.

The line items people forget

These eat bids. Check each one against your quote before you sign.

Dumpster — $350–$650 depending on size and days rented. On a 2-layer tear-off, budget a 20-yard.
Dump fees if billed separately by your hauler.
Permit — varies wildly by jurisdiction. Some cities charge a flat $75, others are percentage-of-job and can hit $400+.
Magnet sweep + lawn protection — $100–$200 of time at the end, plus tarps and boards during the job.
Port-o-let if the job exceeds a couple days.
Delivery fees from your supplier for rooftop delivery or small orders.
Crane or boom rental for inaccessible houses — $400–$900 per day.
Warranty registration — time cost, but also a sales advantage if you're a certified installer.

Worked example: a $23,000 roof

Here's a full pricing breakdown for the 2,400 sq ft gable roof above, using mid-market architectural shingles in a $180/sq labor market, single-layer tear-off, 2-story home.

Line	Qty	Unit	Total
Architectural shingles	27	$110/sq	$2,970
Synthetic underlayment	27	$22/sq	$594
Ice & water shield	2 rolls	$95	$190
Drip edge (eaves + rakes)	240 LF	$1.40/LF	$336
Starter strip	130 LF	$1.20/LF	$156
Ridge cap	90 LF	$4/LF	$360
Nails, boots, flashing, misc	1	$280	$280
Deck repair allowance (2 sheets)	2	$85	$170
Dumpster (20 yd)	1	$525	$525
Permit	1	$175	$175
Labor	24 sq	$180	$4,320
Subtotal			$10,076
Overhead + profit (35%)			$3,527
Customer price			$13,603

That comes out to roughly $566/sq installed. In higher-cost markets or with premium shingles (Malarkey Vista, CertainTeed Landmark Pro, GAF Timberline HDZ + accessory package), you'll see $700–$900/sq installed. In lower markets with builder-grade 3-tab the range drops to $400/sq.

How to present the number

Homeowners reject bids for one of two reasons: the number's higher than they expected, or it's presented in a way that reads cheap. Both are fixable.

Always show good / better / best. Three options in one proposal converts better than a single number, even if the homeowner picks the middle one every time. The top option anchors them; the bottom option makes the middle look reasonable.

Good: 30-year architectural shingle, basic workmanship warranty.
Better: premium architectural (Timberline HDZ or equivalent), synthetic underlayment, 10-year workmanship warranty, upgraded ridge vent.
Best: impact-resistant shingle (insurance discount available in some states), full accessory package, lifetime manufacturer + 25-year workmanship warranty, SatisfactionGuarantee for 12 months.

Include photos of the roof (sketchy spots, existing condition), the full material list, a one-line on the crew and timeline, and a clear payment schedule. Get a signature and a deposit.

Bid mistakes that kill margin

Quoting from Google Earth without a roof walk. Miss one 10-square valley and you've just eaten your overhead.
Eating deck repair inside the square price. Always break it out with an allowance + per-sheet overage.
Using last year's shingle price. Asphalt pricing moved hard in 2021–2023 and still moves seasonally. Call the supplier for a live quote before you commit.
Missing permit, dumpster, or magnet sweep. These aren't rounding errors. Together they're $600–$1,200.
Not charging for steep pitch. A 12/12 is not “just” a 7/12. It's a different crew day rate and a different risk.
Ignoring access. Two-story next to a hedge row with no driveway access is a crane day. Price it.

Try it in ProJobCalc — free

Roofing Calculator

Plug in your measurements and get a material + labor estimate in under 60 seconds.

Frequently asked questions

How many squares are in a 2,400 sq ft roof?: A square in roofing is 100 square feet of finished roof surface. 2,400 sq ft = 24 squares of finished area. Once you add waste (typically 10–15% for architectural shingles, more for cut-up hip roofs), you'll be ordering 27–28 squares of material.
What's a fair labor rate per square for a roof tear-off?: In most U.S. markets in 2026, single-layer tear-off on a walkable pitch (4/12–7/12) runs $120–$180 per square of labor, depending on crew productivity and regional wages. Steep pitch (9/12+) pushes labor to $200–$300/sq because of harness requirements and slower production.
Should I include deck replacement in my bid price?: No — always break it out. Quote a reasonable allowance (e.g., first 2 sheets included) with overage billed per-sheet as a change order. Homeowners understand that rotten deck is invisible until tear-off; they do not understand a $3,000 surprise inside a flat price.
How do I handle a roof with multiple layers I didn't see during estimating?: Document it on arrival with photos, stop work, present the change order before tear-off. Two-layer tear-off typically adds $30–$50 per square in labor plus a larger dumpster. If you write your contract well it covers this: 'Existing layers beyond one billed at actual cost per additional square.'
What's the biggest mistake new roofing contractors make when bidding?: Quoting from Google Earth without walking the roof. You'll miss valleys, misread pitch, miss soft deck, and miss the ugly detail shots around chimneys and skylights. A 20-minute roof walk is the single highest-ROI thing you do on a bid.

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