Paint Coverage Calculator
Calculate how many gallons of paint you need to cover a room based on wall dimensions, door/window deductions, and coverage rate.
Gallons Needed
2 gallons
Gallons Needed vs Room Length
Calculating Paint Coverage
To paint a room, calculate the total wall area minus doors and windows, then divide by the paint coverage rate.
Formula
Wall Area = 2 x (Length + Width) x Height
Paintable Area = Wall Area - (Doors x 21 sq ft) - (Windows x 15 sq ft)
Gallons = (Paintable Area x Coats) / 350 sq ft per gallon
Most interior latex paints cover 350-400 sq ft per gallon on smooth surfaces. Textured walls or dark-to-light color changes may need additional paint.
Example Calculation
A 15 x 12 foot room with 8-foot ceilings, 2 doors, 3 windows, 2 coats.
- 01Wall area = 2 x (15 + 12) x 8 = 432 sq ft
- 02Deductions = 2 x 21 + 3 x 15 = 42 + 45 = 87 sq ft
- 03Paintable area = 432 - 87 = 345 sq ft
- 04With 2 coats = 345 x 2 = 690 sq ft total
- 05Gallons = ceil(690 / 350) = 2 gallons
Frequently Asked Questions
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