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

Seven calculators for estimating and bidding painting jobs from your own costs and your own speed: gallons from wall area after doors and windows, labor hours from your production rate, a full interior room with ceiling and trim, an exterior with crew days, what a materials markup really earns, a bid price 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 14 by 12 bedroom needs 3 gallons for its walls. Every figure is an example for you to overwrite; none of it is a claim about what painting sells for or how fast anyone paints. 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.

• Paint quantity: How many gallons does this room's walls need?
• Labor hours: How many hours will the painting take at your own speed?
• Interior room estimate: What does it cost to paint this room, walls, ceiling and trim?
• Exterior estimate: What does it cost to paint the outside of this house?
• Materials markup: What does a markup on materials actually earn you?
• Bid price from margin: What price gives the margin you want, and why is markup different?
• Job profitability check: Did the job make what the bid said it would?

Every formula was checked

This pack contains 65 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 65 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:

• Walls only; ceilings and trim are on sheet 3. Every wall is the same height. Coverage is the same on every coat; a first coat over new drywall or a big color change can take more, so lower the coverage figure for that job.
• Your production rate is the same on every coat and every wall. Rooms with lots of cutting in (cabinets, built-ins, two colors) run slower: lower the rate for them.
• One color on the walls and one on the ceiling. Overhead is covered by the margin, not costed separately; sheet 6 shows how to cost it explicitly. Ceiling coverage uses the same figure as the walls.
• Walls are measured as a box with gables added; dormers and bump-outs are added to the gable figure. The texture factor raises paint, not hours: lower the production rate too if rough siding slows you. Weather days are not costed.
• Markup is added to cost. Contractor discounts at the paint store lower your cost; enter the price you actually pay. Returned unused paint is not credited.
• 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.
• Every hour is costed at the same labor rate. Change orders the customer paid for should be added to the bid price before comparing, or they show 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.