Homeowners and painting contractors often buy too much or too little paint by guessing room wall square footage manually. Measuring walls, subtracting window and door surface area, accounting for multiple paint coats and wastage creates tedious manual math that leads to wasted money or mid-project supply shortages. This free paint coverage calculator computes net wall area automatically and outputs the exact number of paint gallons required for single or double coat house painting projects.
Tip: Copy gallon estimate to create your painting material shopping list.
Accurate paint volume estimation cuts renovation waste and avoids extra store trips during painting jobs for all residential projects.
This painting estimator uses four simple inputs to generate precise paint gallon totals, usable on mobile phones while measuring room dimensions on-site.
Enter total combined width of all four room walls and standard wall height in feet to calculate raw total wall surface square footage.
Add together all square footage covered by windows, closet doors and entry doors that do not require paint coverage.
Choose 1 coat for primer only or 2 coats for full color finishing, then click Calculate Paint Gallons to view final paint volume including wastage buffer.
A: We use industry standard 400 square feet coverage per gallon of latex paint plus automatic 10% wastage for uneven wall absorption and touch-ups.
A: Yes, input total exterior wall width and height to generate accurate exterior paint gallon estimates for full house repaints.
A: The built-in 10% wastage buffer covers minor texture absorption; heavily textured walls can add an extra 15% manual buffer to your final gallon count.
A: No usage caps, painters and homeowners can calculate paint quantities for unlimited renovation rooms completely free.