The Roofing Estimate Calculator Pack: Seven linked calculators, every formula checked by recalculation

Seven calculators for estimating and bidding roofing jobs from your own prices and your own crew's speed: roof squares from the footprint and the pitch, shingle bundles and underlayment rolls, drip edge, starter and ridge cap from linear feet, tear-off layers and disposal, install labor from squares per crew-day, a bid from a target margin with markup and margin side by side, and a check of estimated against actual hours once the job is done. Start with sheet 1. In the worked example a 48 by 30 foot house at 6 in 12 is 17.89 squares of roof. Every figure is an example for you to overwrite; none of it is a claim about what roofing sells for or how fast anyone works. These are estimates, not financial advice. Every formula was recalculated and checked against an independent implementation before this shipped.

What is in it

7 calculators, one per sheet. Overwrite the blue cells with your own numbers and everything else follows. Nothing is locked, there are no macros, and it opens in Excel, Numbers, LibreOffice and Google Sheets.

• Roof squares: How big is this roof in squares, from the footprint and pitch?
• Shingles and underlayment: What shingle bundles and underlayment rolls does it take, at what cost?
• Drip edge, starter, ridge: What drip edge, starter and ridge cap do the edges take?
• Tear-off and disposal: What does stripping the old roof and getting rid of it cost?
• Install labor: What crew days and labor cost does laying this roof take at your crew's speed?
• Bid from target margin: What bid gives the margin you want, and how is that different from a markup?
• Job profitability check: Did the roof make what the bid said it would?

Every formula was checked

This pack contains 62 formulas. Before it was published, every one of them was recalculated by a spreadsheet engine and compared against an independent implementation of the same arithmetic written in Python. All 62 agreed to within a cent, and the workbook carries a Verification sheet saying so.

That is an unusual thing to be able to claim about a spreadsheet, and it is the main reason to buy this one rather than download a free template. A formula that looks right and is wrong is worse than no formula at all, because you will act on it.

What each calculator assumes

There is a sheet listing this, because a calculator that hides its assumptions is just a number generator:

• Every roof plane has the same pitch, which holds for a plain gable or hip roof. Planes at different pitches: measure each footprint section and run this sheet once per pitch. The footprint is a rectangle; for an L-shaped house add the rectangles. Dormers and porch roofs are extra.
• Bundles per square and roll coverage come off the products you buy. Waste is already in the ordered squares from sheet 1; underlayment gets its own lap allowance on the true roof area. Ice barrier, vents and flashing are not counted here; add them on sheet 6 as other costs.
• Measure the edges on site or from a plan; this sheet does not derive them from the footprint, because rooflines vary. Ridge cap covers ridges and hips at one rate. Valley metal, step flashing and ridge vent are not counted; add them on sheet 6 as other costs.
• Tear-off is costed on roof squares, without the waste allowance. Every layer weighs and strips the same. Decking is an allowance: rot you cannot see until the old roof is off is the reason to state a per-sheet price in the contract.
• Squares per crew-day is a whole-crew rate that already includes starter, edges and ridge. Labor is costed on the exact crew-days; the rounded-up days are for the schedule. A day lost to weather is not costed.
• Overhead is spread evenly across jobs. If your jobs vary a lot in size, spread it by labor hours instead: overhead a year divided by labor hours a year, times this job's hours. The per-square figure is this roof's; a smaller roof carries the same fixed costs over fewer squares.
• Every hour is costed at the same labor rate. Decking replaced beyond the allowance and billed at your unit price should be added to the bid before comparing, or it shows up as an overrun.

What this is not

Not financial, tax or legal advice, and not a recommendation to buy, sell, borrow or sign anything. These are calculators: they show what a choice costs, not which choice is right for you. Where a published rate or threshold is used it is the one current when the pack was built; those change, the arithmetic does not.

Honest about the format

One .xlsx workbook, 7 calculator sheets plus Start Here, Assumptions and Verification. Not a PDF, not a physical product, not a Notion template. Available immediately after purchase; nothing ships.

Refunds

If this isn't what you expected, email me within 30 days and I'll refund you in full. No need to explain. Because it's an instant download I can't take the file back, so I'd rather you just had your money back.