To avoid having too much leftover wall paint, use these formulas to determine how much paint to buy when you start your home improvement painting project.
Total Wall Area:
[Total Length of All Walls] × [Wall Height] = Total Wall Area
Unpainted Areas:
[Window Height] × [Window Width] × [Number of Windows] = Window Area
[Door Height] × [Door Width] × [Number of Doors] = Door Area
Paintable Wall Area:
[Total Wall Area] – [Window Area] – [Door Area] = Paintable Area
Paint to Order:
[Paintable Area] ÷ 350 = Number of Gallons Needed for Smooth Walls
[Paintable Area] ÷ 300 = Number of Gallons Needed for Rough, Textured Walls or Unpainted Wallboard
