How Many Sq Ft Does a Gallon of Paint Cover?

The steps, in order

The short version — each step is explained in full below.

Measure room perimeter and height
Add the length of all walls to get perimeter. Measure the ceiling height. Multiply: perimeter × height = gross wall area.
Subtract openings
Subtract 21 sq ft per door and 15 sq ft per average window. For very large windows, measure individually.
Multiply by coats
Most rooms need 2 coats. Color changes or going dark to light may need 3.
Divide by coverage rate
Divide total square footage to be painted by your paint's coverage rate per gallon (350 for smooth walls, 250 for textured, lower for porous surfaces).
Round up and add buffer
Round up to whole gallons, then add 10–15% for touch-ups. Premium paints with higher coverage rates often work out cheaper per sq ft.

Quick answer

A standard gallon of interior latex paint covers approximately 350 square feet in one coat on smooth, primed drywall. Two coats cover 175 sq ft. Most rooms need two coats. The exact figure varies by paint brand, surface texture, and color change — but 350 sq ft per gallon per coat is the working number.

Formula: paint gallons = (wall area in sq ft × number of coats) ÷ 350.

Coverage by paint type

Different paint formulations behave differently. The 350 sq ft figure is for typical interior latex. Specialty paints can be lower:

·Interior latex (Sherwin-Williams, Benjamin Moore standard): 350–400 sq ft per gallon, one coat
·Exterior latex: 250–350 sq ft per gallon (more is absorbed by exterior surfaces)
·Primer / sealer: 200–350 sq ft per gallon
·Oil-based / alkyd: 350–400 sq ft per gallon (better hide, more coverage)
·Stain blocker / odor blocker: 250–350 sq ft (heavier-bodied)
·Textured / suede / sand finishes: 100–200 sq ft per gallon
·Chalk paint: 100–150 sq ft per gallon (very thin coats by design)

Close-up of a roller sleeve loaded with paint on a tray ramp.

Coverage by surface

The same paint on a different surface covers very different square footage. Always reduce your estimate when the surface absorbs more paint:

Paint coverage per gallon by surface type
Surface	Coverage per gallon	Notes
Smooth drywall (primed)	350 sq ft	The baseline figure most manufacturers cite
Smooth drywall (unprimed)	250 sq ft	Absorbs first coat heavily; prime instead
Knockdown / orange peel texture	275–325 sq ft	Texture adds 10–20% more surface area
Heavy texture / popcorn	200–250 sq ft	Significantly reduces coverage
Plaster	300 sq ft	Smooth plaster similar to drywall
Bare wood (unprimed)	200 sq ft	Wood absorbs heavily; always prime
Primed wood	350 sq ft	Back to baseline
Brick / masonry	150–200 sq ft	Porous; needs masonry primer first
Stucco	150–200 sq ft	Highly textured exterior
Metal (primed)	350–400 sq ft	Smooth and non-absorbent

The formula, step by step

To calculate how much paint you need:

·1. Measure the perimeter of the room (sum of all wall lengths).
·2. Multiply by ceiling height to get gross wall area.
·3. Subtract doors (~21 sq ft each) and windows (~15 sq ft each).
·4. Multiply by the number of coats (usually 2).
·5. Divide by the coverage rate for your paint/surface.
·6. Round up to whole gallons.

Example: 12 × 14 ft room, 8 ft ceilings, 1 door, 2 windows. Perimeter = 52 ft × 8 = 416 sq ft. Minus 21 + (2×15) = 51 sq ft. Net = 365 sq ft. Two coats = 730 sq ft. ÷ 350 = 2.09 gallons. Order 3 gallons (2 for two coats with margin, plus touch-up).

When you need more paint than coverage suggests

The 350 sq ft figure assumes ideal conditions. Order more when:

·Dark over light (or vice versa) — plan on 3 coats, not 2
·Color change (red over white, white over blue) — same: 3 coats
·Textured walls — reduce coverage estimate by 20%
·First time painting a porous surface (raw drywall, fresh plaster) — prime first OR add 30%
·Roller-only application — slightly higher consumption than spray
·Spraying — about 30% more paint due to overspray; check sprayer specs

Cutting in along a ceiling line with a brush, hands only.

Brand-specific coverage rates

Manufacturers publish coverage rates on the can label and product spec sheet. These reflect real-world expected coverage under typical conditions:

·Sherwin-Williams ProMar 200: 350–400 sq ft per gallon
·Benjamin Moore Regal Select: 400–450 sq ft per gallon (higher solids)
·Behr Premium Plus: 250–400 sq ft per gallon (varies by sheen)
·Valspar Signature: 300–400 sq ft per gallon
·PPG Diamond: 350–400 sq ft per gallon

Always check the can. Premium paints typically cover more square footage than budget paints because they have higher solids content. A more expensive gallon often works out cheaper per square foot.

Room-size cheat sheet (8 ft ceilings, two coats)

Skip the math. Find your room size below — the figure is for two coats of standard interior latex on smooth, primed walls, with a small allowance for windows and one door. Always round up; you can’t un-buy a gallon, but you can use leftovers for touch-ups.

Paint needed by room size, with wall area and the quantity to order
Room size	Wall area	Paint needed	Order
8 × 10 ft (80 sq ft)	288 sq ft	1.6 gal	2 gallons
10 × 10 ft (100 sq ft)	320 sq ft	1.8 gal	2 gallons
10 × 12 ft (120 sq ft)	352 sq ft	2.0 gal	2 gallons + quart
12 × 12 ft (144 sq ft)	384 sq ft	2.2 gal	3 gallons
12 × 14 ft (168 sq ft)	416 sq ft	2.4 gal	3 gallons
12 × 16 ft (192 sq ft)	448 sq ft	2.6 gal	3 gallons
14 × 16 ft (224 sq ft)	480 sq ft	2.7 gal	3 gallons
15 × 15 ft (225 sq ft)	480 sq ft	2.7 gal	3 gallons
15 × 20 ft (300 sq ft)	560 sq ft	3.2 gal	4 gallons
16 × 20 ft (320 sq ft)	576 sq ft	3.3 gal	4 gallons
20 × 20 ft (400 sq ft)	640 sq ft	3.7 gal	4 gallons
20 × 24 ft (480 sq ft)	704 sq ft	4.0 gal	4 gallons + quart

Two paint cans open side by side showing different sheens.

Paint sheen matters

The same paint in different sheens covers slightly different square footage because of how the formula is balanced. Higher-sheen paints have more resin and less filler, which usually means slightly lower coverage per gallon but better hide:

·Flat / matte: 350–400 sq ft (highest coverage, hides drywall imperfections, hardest to clean)
·Eggshell: 325–375 sq ft (most popular interior choice, durable, washable)
·Satin: 300–350 sq ft (more washable, more glare, shows roller marks)
·Semi-gloss: 275–325 sq ft (kitchens, bathrooms, trim — must be applied carefully)
·Gloss / high-gloss: 250–325 sq ft (trim, doors, cabinets — shows every flaw)

If you’re mixing sheens on a project (eggshell walls, semi-gloss trim), calculate them separately. Trim usually needs about 10% of the total project area but uses different paint.

Primer: when you need it, how much

Primer isn’t optional in three cases: new drywall, dramatic color change (dark to light or vice versa), or painting over a stain-prone surface (water damage, smoke, glossy paint). Primer coverage runs 200–350 sq ft per gallon — typically less than topcoat because primers are formulated to seal and stick, not to give a finished color.

For a 12 × 14 ft room with 8 ft ceilings (about 416 sq ft of wall area), one coat of primer needs roughly 1.4 gallons. Round up to 2 gallons of primer, plus your normal 2 gallons of finish paint. Total: 4 gallons.

Self-priming “paint and primer in one” products work on most repaints but should NOT replace dedicated primer on new drywall, bare wood, or major color changes. The marketing claim “covers in one coat” assumes ideal conditions that rarely exist in real rooms.

Exterior paint is different

Exterior coverage runs lower than interior — typically 250–350 sq ft per gallon — because:

·Exterior surfaces are usually rougher (siding texture, stucco, brick)
·Exterior paint is thicker (more pigment to resist UV and weather)
·Sun, wind, and temperature affect application thickness
·Most exteriors need a primer coat first, especially over old paint

Rule of thumb for siding: measure the wall area (perimeter × height), don’t subtract for windows under 20 sq ft (the paint accommodates trim work around them), and order 25% more paint than the math suggests. Most professional exterior painters plan on 250 sq ft per gallon to be safe.

Textured wall surface in raking light showing the profile.

Spraying vs rolling

If you’re spraying, plan on 30–50% more paint than rolling for the same area. The overspray, the heavier mil thickness sprayers lay down, and the in-the-cup waste at the end of each session all add up. Professional sprayers minimize this with HVLP equipment, but DIY sprayers tend toward the high end of waste.

Rolling is the most efficient application — closest to manufacturer-quoted coverage rates. Brushing is in between, with more waste on the brush itself and dripping than rolling.

Painting cabinets, doors, and trim

Cabinets and trim are the tricky case because they have far more surface area per square foot of floor than walls do. The published coverage rate (350 sq ft per gallon) is for flat wall area — cabinets need a totally different estimate.

Calculate cabinet paint by adding up all the surfaces you’ll actually coat:

·Door fronts: width × height for each cabinet door. A 15“ × 30” door = 3.1 sq ft per side. Both sides for a typical job = 6.2 sq ft per door.
·Drawer fronts: typically smaller than doors. 15“ × 6” front = 0.625 sq ft per side.
·Cabinet frames (the exposed face frames around openings): about 6 sq ft per linear foot of cabinet run for both sides.
·Interior of doors (the back, paint-grade side): same area as the front.

Typical estimate: a 10-foot run of kitchen base cabinets has roughly 80 sq ft of total paintable surface (doors, drawer fronts, end panels, face frame) — about 4× what you’d guess from floor footprint alone. Plan on 2 quarts for a coat of primer plus 2 quarts of finish paint per coat for a typical 10-cabinet kitchen — total around 1.5 gallons for a full repaint with primer.

Trim and baseboard math

Trim is calculated by linear feet, not square feet, because trim has fixed widths.

·Baseboard (4–6 inches wide): about 0.5 sq ft of paint surface per linear foot
·Door casing (2–3 inches wide on each side, plus top): about 4 sq ft per door opening
·Crown molding (3–5 inches): 0.4 sq ft per linear foot
·Window casing: 3–4 sq ft per average window
·Door (both sides + edges): 40 sq ft per door for an average 30“ × 80” door

For a typical 12 × 14 ft room with one door, two windows, and baseboard around the perimeter: trim adds up to roughly 60–80 sq ft of separate paint surface. One quart of trim paint covers a full room. A full house often needs 2 gallons of trim paint, distinct from the wall paint order.

Apply what you've learned

Calculators that use these techniques

Paint calculator Wall square footage Room calculator Exterior calculator Ceiling Calculator

Frequently asked questions

How many square feet does a gallon of paint cover?+

On a smooth, primed wall, one gallon of interior latex paint covers about 350 square feet in one coat. Two coats = 175 sq ft. Textured surfaces, exterior paint, and color changes reduce that number.

How many gallons of paint do I need for a 12x12 room?+

A 12×12 ft room with 8 ft ceilings has 384 sq ft of wall area. Subtracting one door and one window: ~348 sq ft. Two coats: 696 sq ft ÷ 350 = 2 gallons. Order 2 gallons plus a quart for touch-ups.

How many gallons of paint for 1000 square feet?+

For 1,000 sq ft of wall area at two coats: 2,000 ÷ 350 ≈ 5.7 gallons. Order 6 gallons. If walls are textured or the color change is dramatic, plan on 7.

How much does a quart of paint cover?+

A quart (1/4 gallon) covers about 87 sq ft in one coat. Useful for trim, doors, accent walls, or touch-ups — not for whole-room jobs unless the room is small.

Does primer count as a coat?+

Yes for time and labor, no for coverage math. Primer covers similar square footage but doesn't replace your topcoats. Order primer separately based on its coverage rate (typically 200–350 sq ft per gallon).

Should I buy more paint than I think I need?+

Yes. Order 10–15% extra. You'll want it for touch-ups over the next few years, and color batches can vary slightly so matching later is risky.

Can one gallon cover an average bedroom?+

Maybe one coat, but not two. An average bedroom (12×14 ft, 8 ft ceilings) needs about 350 sq ft per coat — exactly one gallon. For two coats, you need two gallons.

How much paint do I need for a ceiling?+

Ceiling area equals room floor area. A 12 × 14 ft ceiling is 168 sq ft. For two coats: 168 × 2 ÷ 350 = 0.96 gallons. One gallon is usually enough for a single room's ceiling, but heavily textured (popcorn) ceilings can drop coverage to 200 sq ft per gallon — plan accordingly.

Does dark paint require more coats than light paint?+

Yes, almost always. Dark colors have less pigment opacity than whites and tend to streak in one coat. Plan on 3 coats for any dramatic dark color over a light base. Conversely, painting light over dark needs a gray-tinted primer plus 2 topcoats — or 3 topcoats without primer.

How much paint do I need for kitchen cabinets?+

For a 10-foot run of base + wall cabinets (typical kitchen): roughly 1 gallon of primer plus 2 quarts of finish paint per coat. Two coats of finish = 1 gallon of finish paint plus 1 gallon of primer. Total: 2 gallons for a complete cabinet repaint. Double for large kitchens.

How much paint for the exterior of a house?+

A 2,000 sq ft house with 8 ft eaves has roughly 1,400 sq ft of exterior wall area (after subtracting windows and doors). At 250 sq ft per gallon for exterior paint, two coats = 11 gallons. Order a 5-gallon bucket plus 6 gallons, or two 5-gallon buckets to be safe.

How long does paint last in the can?+

Unopened latex paint: 8–10 years if stored above freezing. Opened cans: 2–5 years if the lid is sealed properly. Oil-based: 15+ years unopened, 2–5 years opened. Always strain old paint before using, and discard if it has lumps, sour smell, or won't mix smoothly.

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