Reference
3 car garage dimensions
Three-car garages are commonly planned between 30 x 30 and 40 x 30 three-across, or around 24 x 40 as a tandem, and per-stall width is the number that decides which works.
- Common range
- 30 × 30 to 40 × 30
- Per-stall at 30 ft
- 10 ft
- Per-stall at 40 ft
- 13′ 4″
- Tandem alternative
- 24 × 40
Quick reference
Three-across footprints and per-stall width
Per-stall width computed as interior width ÷ 3
| Footprint | Area | Per-stall width | Gap per side, pickups | Depth behind a pickup |
|---|---|---|---|---|
| 30 × 30 | 900 sq ft | 10′ 0″ | 2′ 3″ | 11′ 0″ |
| 36 × 24 | 864 sq ft | 12′ 0″ | 3′ 9″ | 5′ 0″ |
| 40 × 30 | 1,200 sq ft | 13′ 4″ | 4′ 9″ | 11′ 0″ |
Per-stall width is the single most useful number for a three-car plan: it tells you whether three doors fit the wall.
Layout
Three across or two plus a tandem
Three across needs at least 30 ft of door wall, and the middle stall is always the awkward one. A tandem plan parks two vehicles nose to tail in one deeper bay — roughly 24 x 40 — so the door wall stays at two openings while the footprint grows in depth. Tandem suits a stored or seasonal vehicle; it does not suit three vehicles that all leave in the morning.
Use of space
The third bay is usually a workshop
On a 40 x 30, three planning-envelope pickups occupy 21 ft of the 40 ft width. The remaining 19 ft is not evenly spread in practice: most owners push the vehicles together and keep one full bay clear. That is a 12 to 13 ft working bay with its own door, which is a different building from a 30 x 30.
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.
Planning
Door wall before footprint
Check the door wall first
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.
Keep planning
Next step
Answers
Common questions
Three across needs at least 30 ft of door wall, which is 10 ft per stall. At 36 ft it is 12 ft per stall and at 40 ft it is 13 ft 4 in — the point at which the third bay becomes usable as a workshop.
It works when one vehicle is stored rather than driven daily. A roughly 24 x 40 tandem keeps the door wall at two openings and grows in depth instead, which is cheaper wall for the same vehicle count.
Three 9 ft openings consume 27 ft before spacing, leaving about 3 ft across four pieces of wall. Confirm the spacing your door supplier publishes before fixing the width.
Continue your research
Related planning topics
Background reading on the questions this page raises. None of these pages sells anything.
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