Gallons for the room, before you load the van.
Measure the walls, take out the doors and windows, multiply by your coats and divide by what the can says it covers. Every number, coverage included, is yours to change.
Put the gallons and your labor into a quote by chat: "quote the Kellys, two bedrooms, walls and ceilings, 6 gallons" and Redline lays out the lines.
Try Redline freeHow the math works
Walls
Perimeter times height: 2 x (14 + 12) x 8 = 416 sq ft.
Take out openings
One door at 20 sq ft and two windows at 15 come off: 416 minus 50 is 366 sq ft.
Ceiling, only if it's the same paint
14 x 12 = 168 sq ft. Leave it at 0 when the ceiling gets flat white and the walls get color.
Coats over coverage
366 sq ft x 2 coats is 732. At 350 sq ft per gallon that's 2.09 gallons. Round up to 3, or buy 2 gallons and a quart.
One 14 x 12 bedroom, three ways
8 ft walls, 1 door at 20 sq ft, 2 windows at 15 sq ft, 350 sq ft per gallon.
| Job | Paintable area | Gallons, exact | Gallons to buy |
|---|---|---|---|
| Walls, 2 coats | 366 sq ft | 2.09 | 3, or 2 plus a quart |
| Walls, 1 coat, same color | 366 sq ft | 1.05 | 2, or 1 plus a quart |
| Walls and ceiling in one product, 2 coats | 534 sq ft | 3.05 | 4, or 3 plus a quart |
350 sq ft per gallon is an example. Use the coverage printed on the product you're buying.
What to watch for
- Coverage is a range on the label. New drywall, block, rough stucco and a dark-to-light color change all eat more. Use the low end for those.
- Primer is its own run. Put in the primer's coverage and set coats to 1.
- Trim, doors and cabinets are usually a different product and aren't in this area. Price them as their own lines.
- Ceiling in a different paint? Run it alone: length and width as usual, wall height 0, doors and windows 0, ceiling 1.
- Accent walls are a second run with only that wall's area.
Questions contractors ask
How many square feet does a gallon cover?
Whatever the label on your product says. Manufacturers print a coverage range, and the surface decides where in that range you land. That's why coverage is an input here and not a fixed number.
Should I subtract doors and windows?
For the labor side of a quote, some painters do, since it's area nobody rolls. For buying paint, some leave them in as built-in extra. Set doors and windows to 0 if that's how you work.
How does Redline put the gallons to work?
Tell the chat "quote the Kellys: master bedroom and hall, walls and ceilings, 2 coats, 5 gallons of their color" and Redline drafts an itemized quote with your labor and material lines and a deposit if you take one. Ask it to look up the current price of a gallon on the web first if you like (that uses credits). The quote saves to the Kelly file; you walk them through it or email it from your Gmail. Invoicing with a card pay link is on Solo, $29 a month.
More for painters
Keep reading
- Drywall calculatorRoom size, openings and sheet size into sheets of drywall to order.
- Painting estimate appWalls, trim, doors, coats and prep into a bid with a deposit for paint.
- Painting estimate templateExterior repaint: prep, lead-safe setup, siding, trim, gallons, deposit.
- Job profit calculatorSee what a job really makes after materials, labor and overhead.