Reference
4 car garage dimensions
Four cars are commonly planned as a 40 to 48 foot wide four-across bay or a squarer two-by-two footprint, and the two layouts need very different door walls.
- Four across
- 40 × 30 to 48 × 30
- Per-stall at 40 ft
- 10 ft
- Two-by-two
- 40 × 40, two openings
- Floor used by vehicles
- 37% at 48 × 30
Quick reference
Four-across footprints
Per-stall width computed as interior width ÷ 4
| Footprint | Area | Per-stall width | Gap per side, pickups | Depth behind a pickup |
|---|---|---|---|---|
| 40 × 30 | 1,200 sq ft | 10′ 0″ | 2′ 5″ | 11′ 0″ |
| 48 × 30 | 1,440 sq ft | 12′ 0″ | 4′ 0″ | 11′ 0″ |
A 40′ wide four-across gives 10′ per stall. That is a workable stall width and a very full door wall.
Layout
Four across versus two by two
Four across puts every vehicle on the same wall: nothing is blocked, but the building is 40 to 48 ft wide and the door wall carries four openings. A two-by-two plan on a 40 x 40 halves the door wall to two openings and parks the second pair behind the first. Square footage is nearly identical — 1,200 sq ft against 1,600 sq ft — but the two plans suit different owners: two-by-two only works when two of the four vehicles rarely move.
Site
Manoeuvring room outside matters as much as inside
Stated planning input
Envelopes used in the arithmetic on these pages
| Honda Civic Sedan LX (2024) | 15.33′ × 5.91′publishedVerified source |
|---|---|
| Planning envelope, car | 16′ × 6.5′stated inputPlanning assumption |
| Planning envelope, full-size pickup or SUV | 19′ × 7′stated inputPlanning assumption |
Substitute your own vehicle's published dimensions; every clearance on this page is the footprint minus the envelope.
Use of space
Mixed storage in a four-bay building
A 48 x 30 is 1,440 sq ft. Four pickup envelopes at 7 × 19 occupy 532 sq ft — 37 percent of the floor. The rest is circulation and storage, which is why four-bay buildings are usually ordered with one taller opening for a trailer or boat rather than four identical doors.
Evidence
Where these numbers come from
Evidence record
- Platform calculation
Footprint square footage = width x depth
Computed on this page
- Platform calculation
Remaining clearance = interior dimension minus the parked envelope
Computed on this page
- Verified source
2024 Honda Civic Sedan LX: 184.0 in long, 70.9 in wide, 55.7 in high (15.33 ft x 5.91 ft x 4.64 ft)
2024 Honda Civic Sedan Specifications and Features — American Honda Motor Co.
- Planning assumption
The 7 ft x 19 ft parked envelope used in the clearance arithmetic is a stated planning input, not a measured average of the US fleet
Computed on this page
- Planning assumption
Walk-around and door-swing allowances used on these pages are stated planning inputs chosen by the reader, not requirements
Computed on this page
Computed values are recalculated whenever this page renders. Published figures link to the source document. Planning inputs are shown as inputs so you can substitute your own.
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Answers
Common questions
Four across is commonly 40 to 48 ft wide by 30 ft deep — 1,200 to 1,440 sq ft. A two-by-two plan on a 40 x 40 is 1,600 sq ft with half the door wall.
Four across means nothing is blocked in. Two by two halves the number of openings and the width of the door wall, but the back pair can only leave when the front pair moves.
Most four-bay buildings are ordered with at least one taller opening for a trailer, boat or equipment, because vehicle envelopes only take up about a third of the floor.
Continue your research
Related planning topics
Background reading on the questions this page raises. None of these pages sells anything.
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