How much ceiling paint do I need?
Multiply ceiling length by width, times the coats, then divide by your paint's spread rate, cut for texture. A smooth 12 × 14 ft ceiling is 168 sq ft: two coats at 400 sq ft per gallon take 0.84 gallons, so buy 1 gallon. The same ceiling with popcorn texture needs about 1.4 gallons.
Updated · By the Interior Redesign AI editorial team · Sources cited on the page
Assumption: texture cuts the rate by the ratios in an estimating guide (300, 250 and 200-225 vs 350 sq ft per gallon for smooth). Your paint may differ.
Ceiling paint to buy
1 gallon
0.84 gallons exactly, rounded up to cans.
| Ceiling area | 168 sq ft |
|---|---|
| Coats | 2 |
| Spread rate for this texture | 400 sq ft/gal |
| Paint needed | 0.84 gal |
Planning estimate. Textured and stained ceilings often need a primer coat first; keep a spare quart for touch-ups.
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Key numbers
- Ceiling area
- length × width (the floor area of the room)
- Flat ceiling paint spread rate
- 400-450 sq ft per gallon, depending on texture and porosity (Benjamin Moore Waterborne Ceiling Paint data sheet)
- Texture rates (estimating guide)
- smooth 350, orange peel 300, knockdown 250, popcorn 200-225 sq ft per gallon
- Coats
- 2 for new drywall or a color change; 1 can refresh a sound white ceiling
- Example
- 12 × 14 ft: 1 gallon smooth, 1 gallon + 2 quarts popcorn (2 coats)
Worked example
A 12 × 14 ft bedroom ceiling, smooth vs popcorn
Two coats of flat ceiling paint rated at 400 sq ft per gallon.
- Area: 12 × 14 = 168 sq ft; two coats = 336 sq ft of coverage.
- Smooth: 336 ÷ 400 = 0.84 gallons → 1 gallon.
- Popcorn: rate 400 × 212.5 ÷ 350 = 243 sq ft per gallon; 336 ÷ 243 = 1.38 gallons → 1 gallon + 2 quarts.
Buy 1 gallon for the smooth ceiling, or 1 gallon + 2 quarts if it has popcorn texture.
How we calculate
Ceiling area is length × width. We multiply by the number of coats and divide by the paint's spread rate, then round up to quarts and gallons (three or more quarts round up to a gallon, a shelf-price assumption).
The default rate is 400 sq ft per gallon, the low end of the 400-450 Benjamin Moore publishes for its Waterborne Ceiling Paint, an ultra-flat ceiling paint. The data sheet says coverage depends on surface texture and porosity but gives no textured rate.
For texture we scale your rate by the ratios in Vertigraph's estimating glossary, which lists 350 sq ft per gallon for smooth drywall, 300 for light orange peel, 250 for heavy knockdown and 200-225 for popcorn (we use the 212.5 midpoint). Applying those ratios to a specific paint's rate is our assumption; treat textured results as estimates and keep a spare quart.
Estimates, sources
Planning estimates and published guidelines, not quotes, designs or code rulings. Figures were checked on each source on the date shown. Local prices, your home and your jurisdiction's adopted code decide the real answer.
- Waterborne Ceiling Paint, Ultra Flat N508: technical data sheet (N508 US 013125) (Benjamin Moore, as of Oct 26, 2026): spread rate per gallon 400-450 sq ft, depending on surface texture and porosity
- Coverage rate (estimating glossary) (Vertigraph, as of Oct 26, 2026): secondary estimating guide: smooth drywall 350 sq ft/gal; light orange-peel texture 300; heavy texture or knockdown 250; popcorn ceiling 200-225; real-world coverage runs 10-20% below the can claim
- Protect Your Family from Exposures to Asbestos (last updated Jun 25, 2026) (US Environmental Protection Agency, as of Oct 26, 2026): you generally cannot tell whether a material contains asbestos by looking at it unless it is labeled; if in doubt, treat it as if it does and leave it alone
Ceiling paint by room size and texture
Two coats at a 400 sq ft per gallon smooth rate, rounded up to what you would buy.
| Ceiling | Smooth | Light texture (orange peel) | Heavy texture (knockdown) | Popcorn (acoustic) |
|---|---|---|---|---|
| 10 × 10 ft | 2 quarts | 1 gallon | 1 gallon | 1 gallon |
| 12 × 14 ft | 1 gallon | 1 gallon | 1 gallon + 1 quart | 1 gallon + 2 quarts |
| 15 × 20 ft | 1 gallon + 2 quarts | 2 gallons | 2 gallons + 1 quart | 2 gallons + 2 quarts |
| 20 × 25 ft | 2 gallons + 2 quarts | 3 gallons | 3 gallons + 2 quarts | 4 gallons + 1 quart |
Painting a popcorn ceiling
Popcorn texture soaks up paint and can loosen when it gets wet, so test a small patch first. Many painters spray it, or use a thick-nap roller with light pressure and no back-rolling. Older textured ceilings can contain asbestos, and the EPA notes you generally cannot tell by looking: if in doubt, treat it as asbestos and leave it alone. Have it tested before you scrape or sand.
If you are repainting walls too, the paint calculator covers walls and ceiling together; this tool is for the ceiling alone.
How to use this tool
Measure the ceiling
Length and width of the room in feet or meters.
Pick the texture
Smooth, light orange peel, heavy knockdown or popcorn.
Set coats and the paint's rate
Two coats is the default; enter the spread rate from your paint's data sheet.
Read what to buy
Gallons and quarts, rounded up.
Questions
How much paint do I need for a 12 × 12 ceiling?
144 sq ft; two coats at 400 sq ft per gallon is 0.72 gallons, so buy a gallon. One coat is about 0.36 gallons, two quarts.
Does a popcorn ceiling take more paint?
Yes. An estimating guide puts popcorn at 200-225 sq ft per gallon against 350 for smooth drywall, so plan for roughly 55-75% more paint than a smooth ceiling.
How many coats does a ceiling need?
Two for new drywall, stains or a color change. A single coat can refresh a clean white ceiling in good shape.
Can I use wall paint on the ceiling?
You can, but flat ceiling paint hides roller marks and reflects less glare, and many ceiling paints are made to spatter less when you roll overhead.
Do I need primer on a ceiling?
On new drywall, water stains or smoke-stained ceilings, yes: a stain-blocking primer stops marks bleeding through. A sound painted ceiling usually does not.
How is this different from the paint calculator?
The paint calculator works out walls and ceiling for whole rooms. This one does the ceiling alone and adjusts the spread rate for texture.
Numbers done. Now see it.
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