Ceiling paint calculator

Ceiling area is just length × width, so the only real question is how thirsty the surface is. A flat, smooth drywall ceiling behaves like a wall. Texture adds surface and hollows that hold paint, so plan more. New to this? Paint words explained.

How the ceiling paint calculator works

ceiling area = length × width
paint = area × coats ÷ coverage
smooth: 350 sq ft/gal (8.6 m²/L)  ·  textured: 250 sq ft/gal (6.1 m²/L)

The two planning figures come from the low end of published ranges. Interior latex data sheets such as Sherwin-Williams ProMar 200 list 350–400 sq ft per gallon on smooth, sealed surfaces. Behr’s Premium Plus ceiling paint lists 250–400 sq ft per gallon, depending on application method and porosity, and is formulated for textured, popcorn and acoustic ceilings; the textured setting uses the bottom of that range. If your can gives a figure, type it in under More options and it overrides both.

Worked examples

• How much paint for a 12x12 ceiling: 144 sq ft, the standard bedroom ceiling.
• How much paint for a 10x10 ceiling: when a quart isn’t enough and a gallon is too much.
• How much paint for a 20x20 ceiling: a great room or two-car garage at 400 sq ft.

Ceiling paint vs wall paint

• Flat sheen. Ceilings catch raking light from windows, which shows every roller lap in an eggshell. Ceiling paints dry dead flat to hide them.
• Less spatter. Ceiling paints are made thicker so they don’t rain down off the roller.
• Color. Many ceiling whites go on tinted (pink or blue) and dry white so you can see where you have been.
• One coat or two. A fresh coat of the same white over a sound ceiling often needs only one. New drywall needs primer and then a finish coat or two; see the primer calculator.

Tips

• Paint the ceiling before the walls. Cut in along the edges with a brush first, then roll while the cut line is still wet.
• Roll across the short dimension of the room in strips, and lay off the final passes in one direction, ideally toward the main window.
• Rooms with sloped or vaulted ceilings: measure each slope (its length along the slope × its width) and add them under Add to project list.
• Cover floors completely; even low-spatter ceiling paint drips from the roller ends.

Planning a whole room? The room paint calculator can add the ceiling to the wall order, as in how much paint for a 12x12 room and ceiling. Replacing a popcorn ceiling instead? The popcorn ceiling texture calculator works in bags of texture.