Free contractor calculator
Paint Calculator
Enter a room's dimensions, the number of coats and how many doors and windows to subtract, and this calculator returns the paintable wall area and the gallons of paint to buy. It uses the same 350 sq ft per gallon, per coat coverage estimators rely on.
Your measurements
Result
- Paint to buy
- 3gallons
- Paintable area
- 453sq ft
- Exact need
- 2.6gal
How this is calculated
Wall area
2 × (length + width) × wall height = gross wall area
Paintable
gross − (doors × 21 sq ft) − (windows × 15 sq ft)
Gallons
paintable × coats ÷ coverage, rounded up to whole gallons
Taking this off a real plan?
JobPlumb measures slabs, walls, roofs and runs straight off your drawings, then prices the job and sends a proposal your client accepts online. Free to start, no install.
See JobPlumb estimatingHow to use it
- 1Enter the room length, width and wall height in feet.
- 2Choose how many coats you're applying.
- 3Subtract the doors and windows in the room.
- 4Read the gallons to buy; adjust the coverage if your paint differs from 350 sq ft per gallon.
Paint Calculator, answered
Find the wall area: perimeter (2 × (length + width)) times the wall height. Subtract the doors and windows, multiply by the number of coats, then divide by the paint's coverage, about 350 sq ft per gallon per coat.
Measure it off the real plan in JobPlumb.
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