GUIDE
How to Estimate Paint
A basic paint estimate starts with the total wall area. For a rectangular room, multiply the room perimeter by the wall height, then subtract large doors and windows.
Calculate wall area
Wall area = 2 × (length + width) × height − openings
Next, multiply by the number of coats and divide by the paint manufacturer's coverage rate. Add a modest allowance for application losses and surface conditions.
Coverage is product-specific
Paint coverage varies with the product, surface texture, porosity, color change and application method. The coverage figure printed on the product or technical data sheet should take priority over a generic assumption.
Don't forget ceilings and trim
This calculator focuses on a simple four-wall estimate. Ceilings, doors, trim, cabinets and unusual surfaces should be measured separately when they use different products or colors.