How the ceiling paint calculator works
Ceiling area = Length × Width
Gallons = Area × coats ÷ coverage per gallon
A flat ceiling has the same area as the floor below it. For vaulted or sloped ceilings, measure the slope length instead of the room width.
How much area does a gallon of ceiling paint cover?
| Ceiling | Coverage per gallon | 12×12 room, 2 coats |
|---|---|---|
| Smooth ceiling | 350 sq ft | 1 gallon |
| Light texture | 275 sq ft | 1 gallon + 1 quart |
| Popcorn / heavy texture | 200 sq ft | 1 gallon + 2 quarts |
Tips for painting ceilings
- Use flat ceiling paint — it hides seams and roller marks best.
- Popcorn ceilings soak up paint and can loosen when wet; use a thick-nap roller and light pressure.
- Paint the ceiling before the walls so drips land on surfaces you haven't painted yet.
Frequently asked questions
How much paint do I need for a 12x12 ceiling?
144 sq ft — about 3 quarts for two coats on a smooth ceiling, so most people buy 1 gallon.
Does a ceiling need two coats?
One coat is often enough when refreshing a white ceiling with white ceiling paint. New drywall, stains and color changes need primer plus one or two coats.
How much paint for a popcorn ceiling?
Plan on about 200 sq ft per gallon per coat — roughly double what a smooth ceiling needs.