Painting estimate calculator
Enter the room size, your paint price and your labour rate. You get the paintable area, how many gallons to buy and a price you can quote, worked out the way most painters do it.
How the estimate is worked out
- Wall area is the distance around the room multiplied by the wall height: 2 x (length + width) x height.
- Doors and windows are taken off. We use 20 sq ft for a standard door and 15 sq ft for a standard window.
- The ceiling is added if you include it: length x width.
- Paint needed is the area multiplied by the number of coats, divided by the coverage per gallon. Most interior paints cover 350 to 400 sq ft per gallon on a smooth wall, so we start at 350 to leave a margin.
- Gallons are rounded up, since you can't buy part of a can.
- Labour is the paintable area multiplied by your rate per sq ft. Materials get your markup, and tax goes on the total.
Getting the price right
- Charge for prep. Patching, sanding, caulking and taping often take as long as the painting itself. Add a separate line for it so the client sees the work.
- Rough or porous walls drink paint. Drop the coverage to 250 to 300 sq ft per gallon for new drywall, stucco or bare wood, and plan a primer coat.
- Dark to light colour changes usually need an extra coat. Quote three coats, or a primer and two coats.
- Ask for a deposit on bigger jobs. 25% to 50% up front covers the paint and protects you if the job is cancelled.
- Check whether your state charges sales tax on labour, materials or both. It varies, so set your rate once in your account.
Questions painters ask
How many gallons do I need for a 12 x 12 room?
With 8 ft walls, one door and one window, a 12 x 12 room has about 349 sq ft of wall. Two coats at 350 sq ft per gallon is 2 gallons, or 3 if you include the ceiling.
What should I charge per square foot to paint?
It depends on your area and the job. Many painters charge between $1.50 and $4 per sq ft of wall for labour on a repaint, more for detailed trim, high ceilings or heavy prep. Use your own rate in the calculator.
Does this include trim and doors?
No. Price trim, doors and cabinets as their own lines, usually per item or per linear foot, so the client can see what each part costs.