How many coats?
Two, unless you are refreshing the same colour on a sound painted wall. Any colour change, and anything over filler or bare drywall, needs two.
Paint calculator
Rooms and ceilings — in gallons, with openings deducted.
Frequently asked questions
How much paint for a 12 × 14 ft room?
With 8 ft walls, one door and two windows, about 365 sq ft of wall. Two coats at 350 sq ft per gallon is 2.09 gallons, so 3 gallons, or 2 plus a quart.
How many square feet does a gallon cover?
About 350–400 sq ft per coat on smooth, previously painted walls; 250–300 on heavy texture or masonry.
Should I subtract doors and windows?
Yes. A door is about 21 sq ft and a window 15, so a few openings easily remove most of a gallon.
Is ceiling paint the same?
The area maths is the same, but ceilings normally use a flat ceiling paint, so buy it as a separate can.
Why the can promises more
Printed spread rates assume a smooth, sealed, evenly rolled surface. Texture, porous patches and dark colours all cut real coverage.
What this calculator assumes
- Spread rates: 400 sq ft per gallon on smooth drywall, 350 on light texture, 275 on heavy texture or masonry. Check the can.
- A door is 21 sq ft, a window 15 sq ft.
- Primer covers about 250 sq ft per gallon, one coat.
- Trim, doors and frames are painted from a separate can and are not included.