How much paint do I need for a 12x12 room?

For a 12x12 room with 8-foot ceilings, 1 door, and 2 windows, the paintable wall area is about 333 sq ft. With 2 coats, you need about 1.9 gallons — so 2 gallons. At $35/gallon, that's roughly $70.

How much area does one gallon of paint cover?

One gallon of paint typically covers about 350 square feet with one coat. This can vary based on paint quality, surface texture, and application method. Rough or textured surfaces may require more paint.

Do I need to subtract doors and windows?

Yes. A standard door is about 21 sq ft and a standard window is about 15 sq ft. Subtracting these from your wall area gives you a more accurate paint estimate and can save you from buying extra gallons.

How many coats of paint do I need?

Most projects need 2 coats for even coverage. You may need 3 coats if painting a dark color over a light one (or vice versa), or if using a lower-quality paint. A single coat may work for touch-ups or when using paint-and-primer-in-one over a similar color.

What's the difference between interior and exterior paint?

Interior paint is formulated for low odor, easy cleanup, and durability against scuffing. Exterior paint is designed to resist UV rays, moisture, mildew, and temperature changes. Always use the correct type for your project.

Should I buy extra paint?

It's wise to buy 10-15% more paint than calculated to account for touch-ups, uneven surfaces, and waste. Keep leftover paint sealed for future touch-ups — it's much easier than trying to color-match later.