Garage Size Calculator

The most common single-car garage is 12 x 20 feet (240 sq ft). Typical sizes range from 12 to 16 feet wide and 20 to 24 feet deep, with 12 x 22 and 14 x 24 also popular. The absolute minimum is 10 x 18 feet, but that only suits compact cars, and experts recommend at least 12 feet of width so you can open doors comfortably.

The minimum recommended size for a two-car garage is 20 x 20 feet (400 sq ft), which fits two average vehicles but leaves almost no storage room. For comfortable parking, door opening, and storage, 22 x 24 or 24 x 24 feet is a much better target. The published rule of thumb: add both car widths together plus about 3 feet of clearance on each side of each vehicle.

Take your car's width (mirrors in) and add about 3 feet of clearance on each side. A 6-foot-wide sedan therefore needs at least a 12-foot-wide garage: (12 - 6) / 2 x 12 gives you 36 inches per side, which is exactly what our vehicle-fit calculator reports as comfortable. Wider vehicles like pickups (6.7 ft) push the recommendation to 14 feet wide.

Standard single garage doors are 8 x 7 or 9 x 7 feet, and these cover roughly 80% of US garages. Choose 9 x 7 for SUVs and full-size trucks because it gives extra mirror clearance; a 10 x 7 door is the wide single option. Two-car garages normally take a 16 x 7 double door, or 18 x 7 for easier parking.

It depends on the truck and the garage. A full-size pickup is about 19 feet long and 6.7 feet wide. It technically fits inside a 12 x 20 garage, but our calculator rates that as tight: only 31.8 inches per side and 1 foot of length surplus. For comfortable parking we recommend 14 x 26 feet, paired with a 9 x 8 door.

Seven feet is the standard residential garage door height. Move up to an 8-foot door if you drive a truck or SUV with a roof rack, antenna, or lift kit, or if the door opening serves taller vehicles. RV and boat storage needs 10 to 14 feet of height. As a rule, size the door height at least 1 foot above your tallest vehicle's height.

The bare minimum for a three-car garage is 30 feet wide by 20 feet deep. Most comfortable 3-car designs run 32 x 22 to 32 x 24 feet, which leaves room to open doors and walk between cars. Our 3+ car sizer uses a published layout rule: sum the vehicle widths, add 2 feet between adjacent cars, add 3 feet on each side, and round up to even feet.

Plan on roughly 2 to 3 feet of clear space on each side of the vehicle. With a 6-foot-wide sedan in a 12-foot-wide garage you get 36 inches per side, which is comfortable. Below 18 inches per side the calculator flags the fit as tight. Between two cars in a shared garage, allow at least 2 feet so doors do not collide.

A 2-foot-deep shelf strip across a 20-foot front wall consumes 40 sq ft (about 9% of a 20 x 22 garage) and still leaves a 20-foot parking depth. An 8-foot workbench with 3 feet of standing room needs 5 feet of depth. Always re-check the remaining parking box against your car's dimensions before committing to a layout.

Standard framing practice: the rough opening is the door width plus 3 inches and the door height plus 1.5 inches. So an 8 x 7 foot door needs a 99 x 85.5 inch rough opening, and a 16 x 7 double door needs 195 x 85.5 inches. Also leave about 12 inches of headroom above the opening for the opener and tracks.

Eight feet is the standard residential garage ceiling. If you want overhead storage racks, a taller vehicle, or a car lift, consider 10 to 12 feet. Higher ceilings pair naturally with 8-foot garage doors, which also solve clearance problems for trucks and roof boxes.