Paint Calculator

A 12x12 room with 8-foot ceilings has about 384 square feet of wall area. After subtracting a door and two windows (roughly 50 sq ft), you need about 334 sq ft of coverage. One gallon covers ~350 sq ft, so one gallon is usually enough for one coat. For two coats, buy two gallons.

One gallon of interior paint covers approximately 350-400 square feet on smooth surfaces. Textured walls reduce coverage to 250-300 square feet per gallon. This calculator adjusts automatically based on your wall texture selection.

You need primer when painting over dark colors, new drywall, patched areas, or stained surfaces. Paint-and-primer combos work for same-color touch-ups or light-to-light color changes. This calculator recommends primer when you select the dark color option.

Most interior paint jobs need two coats for even coverage. You might get away with one coat when painting a similar color. Going from dark to light (or vice versa) may require three coats. Using a tinted primer reduces the number of topcoats needed.

Flat/matte works best for low-traffic areas like bedrooms and ceilings. Eggshell is the most popular choice for living rooms and dining rooms. Satin is ideal for kitchens, bathrooms, and hallways. Semi-gloss works for trim, doors, and cabinets.

Ceiling paint is usually sold separately. If your ceiling needs painting, toggle the ceiling option in this calculator. Ceilings typically use flat white paint, which covers well in one coat unless covering stains or dark colors.