A starting job
Pick a common call to fill the squares, membrane, tear-off, and extras. Changing a kit never overwrites hours or material costs you have already typed.
The roof
Length and width are the building plan. Slope barely changes a flat roof. These are starting points, not a code opinion.
Hours and counts
Squares, membrane squares, and tear-off start from the plan. Membrane hours apply to the wasted squares. Change them when the site disagrees.
Materials and your costs
Payroll burden covers employer taxes, workers’ compensation, liability insurance, and paid time off. A square special written on the plan never sees it — or the membrane mil.
Your bid
- Plan / roof
- Squares / membrane squares
- Tear-off
- Insulation / parapet
- Membrane share of direct
- Crew hours
- Loaded labor
- Materials
- Travel, welder, extras
- Overhead
- Total cost
- Profit
- Price per square
- Effective hourly rate
- Walk-away price
A bid link carries your own rates — wage, burden, overhead, and target margin — so the page reopens exactly as you left it. Send it to yourself or your crew. The numbers ride after the #, which is never sent to a server, so copying a link uploads nothing. The customer should get the price, not the link.
Where the hours go
Transparent arithmetic from your own inputs. The starting slopes, waste, hours, and material rates are common ballpark figures, not a building-code opinion, a permit, a wind-uplift rating, a warranty, or an engineering stamp. Time your own crews and replace them.
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 customer — 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.
Common questions
Why can a competitor advertise “$650 a square”?
Usually because the special is written around one specific job, and that job is a preset here: a 12-square TPO-45 recover over an existing membrane on a one-story garage. It really does price low. What the per-square number cannot see is recover versus tear-off, wet insulation, parapet flashing, drains, curbs, and story count. Price your actual roof beside the special and the gap becomes a list of line items instead of an argument about who is honest.
Why does a tear-off cost so much more than a recover for the same square footage?
A recover installs new membrane over what is already up there. A tear-off strips the old roof down to deck first — labor and disposal that a recover skips entirely. Adding wet insulation on top of that means replacing waterlogged polyiso discovered under the old membrane, which is exactly the kind of cost a flat per-square special from a garage recover was never priced to cover.
Why do parapet walls, drains, and curbs get their own line items?
Because they are flashed and sealed individually, not spread across the field membrane. Eighty linear feet of parapet on a commercial building is eighty feet of detail work at the wall-to-roof transition. Each roof drain and HVAC curb is its own penetration that has to be flashed watertight. None of that scales with plan squares the way flat field membrane does.
Does this check building code, wind-uplift rating, or engineering requirements?
No. Membrane rates, waste, and insulation figures here are common starting points for residential and light-commercial bids, not a building-code opinion, a permit, a wind-uplift rating, or an engineering stamp. Confirm the jurisdiction and a qualified professional before sending a price, especially on multi-story or high-wind-zone work.
Is my data uploaded anywhere?
No account and no network requests — the calculator runs entirely in your browser. Your bid is saved in this browser’s local storage so it is still here next visit, and the optional usage counter records only which features were used and the day, never your roof dimensions, wages, or prices.
What’s the difference between the bid price and the walk-away price?
The bid price already includes your target margin on top of labor, materials, and overhead. The walk-away price is the total cost underneath it — membrane, tear-off, insulation, parapet, drains, curbs, and permit — the point below which the job stops being profitable at all. Typing a price you are considering shows you the margin or the loss before you send it.