How Much Paint for a Whole House — 3,000 sq ft Walls?
Painting 3,000 sq ft of wall area minus 300 sq ft of openings with one coat requires about 8 gallons.
How to use this tool
- Measure each wall (length x ceiling height) and add the areas together.
- Estimate the area of doors and windows you won't paint and enter that to subtract.
- Choose the number of coats — two is standard.
- Enter the coverage rate from your paint can (default 350 sq ft/gal).
- Read the gallons to buy, rounded up to whole cans.
Calculate total paint gallons needed for a full interior repaint of an entire house.
Frequently asked questions
- How many gallons of paint do I need for a room?
- Add up the wall area, subtract doors and windows, multiply by coats, then divide by about 350 sq ft per gallon. A typical 12x12 room with 8 ft ceilings needs roughly 2 gallons for two coats.
- How much does one gallon of paint cover?
- About 350-400 sq ft per coat on smooth, primed drywall. Rough, textured, or unprimed surfaces can drop that to 250 sq ft or less, so check the spread rate on your can.
- Do I need primer, and does it count as a coat?
- Use primer over bare drywall, stains, or a big color change. Yes — count primer as an additional coat when estimating, since it consumes paint at a similar rate.