Garage paint calculator

A typical garage needs about 3 gallons + 3 quarts

Based on a standard 22 × 20 ft garage with 9-ft ceilings, the walls work out to about 720 sq ft after subtracting 1 door and 1 window. A standard two-coat repaint needs roughly 3 gallons + 3 quarts of quality interior paint. The recommended finish for a garage is satin — more on why below.

Prime Bare Drywall, Sheathing, And Block

Unfinished garage walls are the porous, thirsty kind. New drywall needs a drywall primer or the joints and paper soak unevenly; OSB and plywood sheathing want a sealing primer or they swell and telegraph the grain; bare block needs a masonry block filler. Skipping primer means burning two or three coats of finish paint to bury the blotchiness. One primer coat plus two finish coats is cheaper and more even than four coats of finish alone, and it bonds far better.

Choose A Tough, Washable Finish

A garage is a workshop, not a den, so durability beats looks. Satin or semi-gloss in a quality interior or interior/exterior paint wipes off the road grime, exhaust film, and handprints that flat would absorb. Semi-gloss is the most scrubbable and the easiest to hose attention onto a greasy spot. Look for mildew resistance if the garage is unheated or humid, and an interior/exterior product if it goes through hard winters or summers.

Skip A Color That Shows Every Mark

Bright white walls look clean for about a week, then every tire scuff, oil fleck, and dusty handprint stands out. A medium-light gray, warm greige, or soft tan hides the daily grime without turning the space into a cave. Keep it light enough to make the most of the usually-poor garage lighting — you still need to see what you are working on — but not so white that it becomes a full-time cleaning chore.

The Floor Is A Separate Job

Do not roll wall paint onto the slab; it will not survive tires and foot traffic. The floor needs a dedicated concrete or epoxy floor coating, and it covers far less per gallon than wall paint — figure around 225 sq ft per gallon in two coats, so a 440 sq ft two-car floor needs roughly four gallons. The slab also must be clean, etched, and fully cured first, which is why most people coat walls one weekend and the floor another.

How the garage paint math works

Wall area is perimeter × ceiling height: (2 × 22 + 2 × 20) = 84 ft of perimeter, times a 9-ft ceiling, equals 756 sq ft of gross wall. We subtract 21 sq ft per door and 15 sq ft per window, leaving about 720 sq ft of paintable wall. Multiply by the number of coats, divide by a coverage rate of about 388 sq ft per gallon, and round up to the nearest quart — that is the number you take to the store. Change any input in the calculator above and it recalculates instantly.

Paint needed by coats

Two coats is the right default for almost every repaint. Use one coat only for a same-color refresh, and three for dark-over-light changes or vivid colors that cannot hide in two. The ceiling adds 440 sq ft (length × width) when you choose to paint it — usually a separate flat-white product, so most people buy a dedicated gallon for it.

What it costs to paint a garage

Doing it yourself, the paint for two coats runs about $150–$263 (roughly 3.75 gal at $40–$70 a gallon), plus $50–$100 in supplies — rollers, brushes, tape, trays, and a drop cloth. That is your whole cost if you bring the labor.

Hiring a painter changes the math: most pros charge $2–$5 per square foot of floor area, so a 440 sq ft garage lands around $880–$2,200. Labor is 75–95% of an interior bill because prep, cutting in, and cleanup eat the hours. For a full paint-plus-labor breakdown, use the paint cost calculator.

Paint cost by brand

Coverage is similar (about 350–400 sq ft per gallon) across the major interior lines, so the price tier is what moves your bill. These are current per-gallon prices for the brands the calculator can price for you — pick one in the result panel above and it multiplies your gallons for this garage into an exact paint cost:

• Bedroom paint calculator
• Master Bedroom paint calculator
• Bathroom paint calculator
• Kitchen paint calculator
• Living Room paint calculator
• Dining Room paint calculator
• Hallway paint calculator
• Nursery paint calculator
• Home Office paint calculator
• Basement paint calculator

• Interior paint calculator (any room)
• Paint cost calculator (paint + labor total)
• How many coats do I need?