How Much Paint Does a Garage Need?
Garages are larger than most interior rooms and often have higher ceilings, which means they need significantly more paint than a standard bedroom or living room. A single car garage measuring 12x20 with 10ft ceilings has approximately 640 square feet of wall area before deductions. After deducting one large garage door and one entry door, the paintable wall area is around 520 square feet. At 400 square feet per gallon with two coats, that equals about 2.6 gallons.
A standard two-car garage measuring 20x20 with 10ft ceilings has approximately 800 square feet of gross wall area. After deducting two garage doors and one entry door, the paintable area is around 600 square feet — requiring about 3 gallons for two coats. Most homeowners buy 4 gallons to cover the ceiling and have extra for touch-ups.
In litres, a single car garage needs 7 to 10 litres for two coats on the walls. A two car garage needs 12 to 15 litres. Buying paint in 5 litre tins gives the best value for garage projects.
Garage Paint Calculator — Reference Table
| Garage Size | Type | 2 Coats (walls) | Litres (2 coats) |
|---|---|---|---|
| 10x20 | Single car (small) | 2.0 gal | ~7.5 litres |
| 12x20 | Single car (standard) | 2.6 gal | ~10 litres |
| 20x20 | Two car (standard) | 3.2 gal | ~12 litres |
| 22x22 | Two car (large) | 3.8 gal | ~14 litres |
| 24x24 | Two car (oversized) | 4.2 gal | ~16 litres |
| 24x36 | Three car | 5.5 gal | ~21 litres |
Best Paint Finish for a Garage
Satin or semi-gloss is the best finish for garage walls. Garages are exposed to moisture, oil splatter, exhaust fumes, and general dirt — satin and semi-gloss finishes resist staining and can be scrubbed clean. Semi-gloss also reflects more light which makes garages feel brighter and easier to work in.
Avoid flat or eggshell finishes in garages. They absorb oil and stains, cannot be scrubbed, and will look dirty within months of a garage being in regular use.
Best Paint for Garage Walls
If your garage walls are drywall or plywood, any durable interior latex paint in satin or semi-gloss finish will work. If your garage walls are bare concrete, cinder block, or masonry, you must use a masonry paint or apply a masonry primer before painting with standard latex.
Rust-Oleum Zinsser Watertite is the best choice for concrete and masonry garage walls — it waterproofs while painting. Behr Premium Plus Interior/Exterior in semi-gloss is a reliable all-purpose choice for drywalled garages. Sherwin-Williams Duration in satin is the premium option for maximum durability and washability.
Garage Floor Paint — How Much Do You Need?
Garage floor paint is a separate calculation from wall paint. A standard 20x20 garage floor has 400 square feet. Epoxy floor coatings typically cover 200 to 250 square feet per gallon, meaning a 20x20 floor needs 1.6 to 2 gallons per coat. For two coats, buy 3 to 4 gallons of epoxy floor coating.
Always use dedicated epoxy floor coating for garage floors — never standard wall or ceiling paint. Epoxy bonds chemically to concrete and withstands oil, chemicals, abrasion, and heavy vehicle traffic. Standard paint will peel off a garage floor within weeks.
Tips for Painting a Garage
Clean walls thoroughly before painting. Garage walls accumulate grease, oil, and exhaust deposits. Degrease with TSP cleaner and let dry fully before applying any paint or primer.
Prime bare concrete and masonry. Never apply latex paint directly to unpainted concrete or cinder block without a masonry primer. The paint will flake off within months.
Paint walls before the floor. Always complete wall and ceiling painting before applying any floor coating. Drips and spatters from wall painting will be covered by the floor coat.
Ventilate well during painting. Garages have limited airflow. Keep the garage door open and use a fan to exhaust fumes during and after painting.
Buy extra for concrete walls. Bare concrete and cinder block are highly porous and absorb the first coat heavily. Buy 20% more paint than calculated for bare masonry surfaces.
Related Paint Calculators
- Ceiling Paint Calculator →
- Living Room Paint Calculator →
- Bedroom Paint Calculator →
- Primer Calculator →
- How Much Paint for a 12x12 Room →
- Free Paint Calculator →
Frequently Asked Questions
How much paint do I need for a garage?
A standard 2-car garage needs 3 to 4 gallons for two coats on the walls. A single car garage needs about 2 to 2.5 gallons. Use the calculator above and enter your exact dimensions for a precise estimate.
What paint finish is best for a garage?
Satin or semi-gloss is best for garage walls. These finishes resist moisture, oil, and dirt and are easy to wipe clean. Avoid flat paint in garages — it absorbs stains and cannot be scrubbed.
Do I need special paint for a garage?
Use a durable latex or masonry paint for garages. If walls are bare concrete or cinder block, use masonry paint or apply a masonry primer before painting with standard latex.
How much paint for a garage floor?
A standard 20x20 garage floor needs 3 to 4 gallons of epoxy floor coating for two coats. Always use dedicated epoxy floor coating — never standard wall paint on garage floors.
How many litres of paint for a garage?
A single car garage needs 7 to 10 litres for two coats on the walls. A two car garage needs 12 to 15 litres. Buy paint in 5 litre tins for best value.
Should I paint garage walls before or after the floor?
Always paint walls and ceiling before the floor. Drips and spatters from wall painting will be covered by the floor coating. Painting the floor last protects it from damage during wall painting.