The roof
One row per section. Footprint is the area on the ground, not the shingle surface — pitch turns it into squares. Tear-off layers is how many existing roofs come off (0 for a new deck).
Material and waste
Picking a covering fills in material and install hours, but never overwrites a number you have already changed. Replace them with your current supplier invoice and a rate timed from your own crew.
Your costs
Steepness is applied automatically: 7/12–9/12 adds 25% labor, 10/12–12/12 adds 50%, steeper than 12/12 doubles it. Those steps are starting points, not a safety rating.
Hand the customer a proposal
The price above is for you. This is the page you print or save as a PDF and give to the homeowner — your details, their details, the scope, the deposit split, and a line for them to sign. Your business details are saved on this device so you only type them once; the customer’s details are never saved.
Everything on the printed page is text you typed or a number this calculator worked out. It contains no warranty, lien, or cancellation wording — those depend on your jurisdiction and your contract, and this tool is not the place to invent them.
Your bid
- Roof squares (surface)
- Squares after waste
- Tear-off squares
- Labor hours
- Loaded labor
- Material & accessories
- Dump & dumpster
- Permit & other
- Overhead
- Total job cost
- Job profit
- Price per square
- Price per house sq ft
- Effective hourly rate
- Walk-away price
Where the labor goes
Transparent arithmetic from your own inputs. The starting material and labor rates are common ballpark figures, not a supplier quote, a benchmark, or a guarantee — replace them with your invoice and your crew.
Common questions
How do I turn a house's square footage into roofing squares?
You cannot, directly — that is the mistake this tool exists to stop. Enter each section's footprint (the area it covers on the ground) and its pitch, and the calculator multiplies the footprint by √(1 + (rise ÷ 12)²) to get actual roof surface, then divides by 100 to get squares. A 1,800 sq ft footprint at 6/12 is about 20 squares of roof, not 18. At 12/12 it is over 25. Bidding the footprint number buys you roughly one square of material short for every eight you ordered.
Why does pitch change the price twice?
Because it changes two different things. Steeper pitch means more surface for the same footprint, which is a material and a labor quantity. It also means slower, harder work on that surface, which is a labor rate. The second effect is the steepness multiplier: 1.0 up to 6/12, 1.25 through 9/12, 1.5 through 12/12, and 2.0 above that, applied to install and tear-off hours. Those steps are common shop starting points, not OSHA categories or a safety determination — a 12/12 walk-and- stage decision is yours, not the calculator's.
Does waste apply to the tear-off as well as the new roof?
No, and that is deliberate. Waste covers cuts, starter, ridge, and valleys on the new covering, so it is added only to the material squares that underlayment and covering are priced from. Tear-off follows the existing surface multiplied by how many layers are actually coming off, and dump cost follows those tear-off squares. A two-layer strip on a section is twice the tear-off and twice the landfill, but it does not double the shingles.
Why price the garage and the porch as separate sections?
Because they are usually a different pitch and a different number of existing layers, and a blended rate cannot see that. A steep detached garage or a porch cover carrying three layers is priced at its own pitch factor, its own steepness multiplier, and its own tear-off squares. One averaged "roof" row quietly moves cost from the hard section onto the easy one and leaves the bid short by whatever the hard section actually is.
Why isn't a 20% margin the same as adding 20% to my cost?
Margin here is a share of the final price, which is how the customer's number is quoted and how your P&L reads it: price = job cost ÷ (1 − margin). Overhead, separately, is a markup on the direct cost of the job — office, sales, and the insurance that is not already in payroll burden — and it is applied before margin, never to itself or to the profit. Marking a $10,000 cost up by 20% gives $12,000 and a 16.7% margin. Targeting a 20% margin gives $12,500. That gap is the whole job's profit on a small reroof.
How much more does a metal roof cost than asphalt shingles?
More than the material line alone shows. The covering presets here start 3-tab asphalt at $95 a square and architectural asphalt (this calculator's default) at $140, but standing-seam metal starts at $480 a square — a bit over three times the architectural material cost, and stone-coated steel and concrete tile sit in between at $360 and $420. Install labor climbs with it: 1.5 hours a square for 3-tab, 1.8 for architectural, up to 3.5 for standing-seam metal, because seaming and flashing panel roofing takes longer per square than nailing a shingle course. Picking a covering in the calculator fills material, underlayment, and install hours together, so the price gap you see includes both the pricier material and the slower crew day, not material cost by itself.
Is my bid data uploaded anywhere?
No. There is no account and no network request — every figure stays in this browser, including the business details saved for the printed proposal, which "Forget my business details" clears. "Copy share link" encodes the sections, rates, and deposit terms into the page's own URL hash so a partner or office can open the same bid; nothing is sent to a server. The optional local usage counter records only which features were used and the day, never your roof measurements, wages, costs, or prices, and the checkbox in the footer turns it off.