Paint Coverage Calculator
Accurate paint estimation prevents mid-project trips and batch-matching problems. This calculator uses standard coverage rates to determine gallons needed based on wall area, surface texture, number of coats, and paint type.
Room / Area Details
Coverage rates assume proper surface preparation. Porous surfaces, extreme color changes, and high-build coatings may require additional material.
Standard Paint Coverage Rates
| Surface | Coverage per Gallon |
|---|---|
| Smooth drywall (painted) | 350–400 ft² |
| Orange peel / light texture | 250–350 ft² |
| Heavy knockdown / stucco | 200–300 ft² |
| Bare drywall (primed) | 300–350 ft² |
| Bare wood | 200–300 ft² |
| Exterior siding | 250–350 ft² |
Frequently Asked Questions
How many gallons of paint for a 12×12 room?
A 12×12 room with 8-foot ceilings has about 342 net square feet of wall area (after deducting 2 openings). At 400 sq ft per gallon, that is about 0.85 gallons per coat — round up to 1 gallon per coat, 2 gallons total for two coats.
Do I need primer?
Primer is recommended for: bare drywall, bare wood, stain blocking, dramatic color changes (dark to light), and high-gloss over flat. Many premium paints include primer, but a dedicated primer provides better results on new surfaces.