Garage
Garage and workshop dimensions
A garage is sized by what happens after the car stops, not by the car.
On this page (7 sections)
Short answer
Two mid-size cars at 78 in (198 cm) wide over the mirrors, with 30 in (76 cm) to open a door at each side and between them, need 20 ft 6 in (6.25 m) of clear width. Depth follows the longest vehicle plus 3 ft (91 cm): 22 ft (6.7 m) for a car, 26 ft (7.9 m) for a full-size pickup. Anything stored on a wall is subtracted from those figures, not added to the building.
The numbers, at a glance
- Single garage, clear
- 12 x 22 ft (3.7 x 6.7 m)14 ft (4.3 m) wide if you want a bench
- Double garage, clear
- 22 x 24 ft (6.7 x 7.3 m)20 ft (6.1 m) parks two cars but opens one door
- Car door swing
- 30 in (76 cm)From body face, not from the kerb line
- Standard door opening
- 16 x 7 ft (4.9 x 2.1 m)Double; 9 x 7 ft (2.7 x 2.1 m) single
- Headroom above opening
- 12 to 18 in (30 to 46 cm)Low-headroom track runs at 4.5 in (11 cm)
- Backroom behind opening
- Door height plus 18 in8 ft 6 in (2.6 m) for a 7 ft door
- Workbench height
- 34 to 36 in (86 to 91 cm)32 in (81 cm) for heavy or hand work
- Clear under overhead racks
- 84 in (213 cm)Below that you walk into your own storage
Every other room is planned around people. A garage is planned around a 16 ft (4.9 m) object that has to be driven in, stopped and walked around, and around the fact that anything hung on the walls is subtracted from that manoeuvre rather than added to the building. That fixes the order of decisions: parking rectangle first, opening second, wall storage third, workshop last.
Why two cars need 20 ft 6 in of clear width#
Garage sizes are quoted structurally. A plan that says 20 x 20 ft measures the outside of the frame, and with 2x4 studs and plasterboard on both faces the clear internal width is nearer 19 ft 2 in (5.84 m). Ten inches are gone before a shelf is fitted, so measure finished faces, the way how to measure a room properly sets out.
That clear width is spent on three gaps, not two. Two mid-size vehicles measure about 78 in (198 cm) across the mirrors, so the cars take 156 in (396 cm). A car door needs roughly 30 in (76 cm) from the body to open far enough that an adult can step out facing forward, and that gap is needed at each side wall and once between the cars: 90 in (229 cm). The total is 246 in, which is 20 ft 6 in (6.25 m) of clear width. That sum is worked through in garage sizes: single, double and triple, and the swing arc behind the 30 in figure is in car parking space and door swing dimensions. Thirty inches is also a comfortable secondary route indoors, for the same reason a body edging past an obstruction sets walkway and circulation widths.
| Garage | Nominal | Clear internal | What it actually does |
|---|---|---|---|
| Single, minimum | 12 x 22 ft | 11 ft 2 in x 21 ft 2 in (3.4 x 6.45 m) | One car, one door open, no bench |
| Double, builder | 20 x 20 ft (6.1 x 6.1 m) | 19 ft 2 in (5.84 m) | Two cars or two open doors, not both |
| Double, working | 24 x 24 ft (7.3 x 7.3 m) | 23 ft 2 in (7.06 m) wide | Two cars, both doors, shelves on one wall |
| Triple | 32 to 36 ft (9.8 to 11.0 m) wide | Two doors, not three | Third bay becomes the workshop |
Headroom, sideroom and backroom at the opening#
A garage door has four dimensions and one of them is on the price list. The opening is 9 x 7 ft (2.7 x 2.1 m) for a single and 16 x 7 ft (4.9 x 2.1 m) for a double, with 8 ft (2.44 m) high leaves where a roof box or a van has to pass. Around it sit headroom of 12 to 18 in (30 to 46 cm) above the opening for the spring shaft, sideroom of 3.75 to 6 in (95 to 150 mm) each side for the track, and backroom equal to the door height plus 18 in (46 cm), so a 7 ft door needs 8 ft 6 in (2.6 m) of unobstructed ceiling behind the opening. The low-headroom exceptions are in garage door sizes, headroom and backroom.
Every 16 in of shelf costs 16 in of parking#
Wall storage quietly undoes the parking arithmetic. Sixteen inches (41 cm) of shelf depth holds boxed goods and 24 in (61 cm) holds bulk and paint, but either figure applies twice on two long walls: 24 in shelving down both sides of a 24 ft garage returns the clear width to 20 ft. Keep the long walls shallow and spend depth on the end wall in front of the bonnets, as garage shelving and overhead storage dimensions sets out. Bikes force the issue, because a hanging bike projects 24 to 30 in (61 to 76 cm) at exactly door-swing height: bike and sports gear storage dimensions ranks the options by what each costs in floor width.
| Wall item | Depth | Height off floor | What it takes from the bay |
|---|---|---|---|
| Shallow shelving | 12 to 16 in (30 to 41 cm) | 12 in (30 cm) up | 16 in per wall |
| Workbench | 24 to 30 in (61 to 76 cm) | Top at 34 to 36 in (86 to 91 cm) | 30 in plus 36 in (91 cm) to stand |
| Overhead rack | 48 in (122 cm) wide | Underside at 84 in (213 cm) | Ceiling only, if the door clears it |
Bench height is worth setting from your own body: 34 to 36 in (86 to 91 cm) for assembly, 32 in (81 cm) when you need weight over the work. Workbench height, depth and clearances gives the range by task, and the shelf above it obeys the same beam arithmetic as any other, which the shelf span and sag calculator runs.
Machines need infeed, not footprint#
A workshop is sized by the material passing through the tools, not by the tools. A table saw with a 3 ft (91 cm) footprint needs 8 ft (2.4 m) in front and 8 ft behind to break down a full sheet, 19 ft (5.8 m) of run in one axis, and a mitre saw wants 10 ft (3.0 m) of side support. Hence the machines on wheels that borrow the bay when the car is out. Workshop tool clearances: saws, benches and infeed gives the numbers per machine, and where the floor doubles as training space, garage gym layout dimensions covers the conflict between a squat rack and a bonnet.
The house door, the 7.75 in step and the fall to the opening#
Two constraints meet here. The IRC requires the door between garage and dwelling to be a solid or 20-minute fire-rated leaf at least 1.375 in (35 mm) thick, and the landing rule limits the step: the garage floor may sit up to 7.75 in (197 mm) below the threshold only where the door does not swing out over it, otherwise the difference is 1.5 in (38 mm). The floor should fall to the main opening at about 1 in per 8 ft (1 per cent). Garage to house door, step and landing dimensions sets out the combinations that work. The landing on the house side usually belongs to the mudroom sizes and layouts, and the code wording sits in the standards and codes reference.
Charging at 18 to 48 in, where the port is#
Charging is a placement problem before it is an electrical one. Cables run 15 to 25 ft (4.6 to 7.6 m), but one crossing a bay to reach a port on the far wing is a trip hazard on a wet floor for the life of the car. Mount the unit on the wall the port faces, connector between 18 and 48 in (46 and 122 cm) from the floor and clear of the door swing; EV charger placement, heights and cable reach works through port positions by vehicle. Sockets sit higher here than the skirting heights in socket and outlet heights, above bench level, because a garage wall works for its whole height.
In this section#
- Bike and sports gear storage dimensionsBikes hang on vertical hooks at 16 in (41 cm) centres if you alternate the heights, and need 18 in (46 cm) of swing to come off. Ski, board and gear sizes too.
- Car parking space and door swing dimensionsA car door needs 30 in (76 cm) of clear space beside the body. US stalls are 9 x 18 ft (2.74 x 5.49 m), UK bays 2.4 x 4.8 m, and neither allows for a garage.
- EV charger placement, heights and cable reachDock the connector 42 to 48 in (107 to 122 cm) above the floor, on the wall the charge port faces. A 15 ft (4.6 m) cable really reaches 11 ft 6 in.
- Garage door sizes, headroom and backroomSingle garage doors are 9 x 7 ft (2.74 x 2.13 m), doubles 16 x 7 ft (4.88 x 2.13 m), and every one of them needs 12 in (305 mm) of headroom above the opening.
- Garage shelving and overhead storage dimensionsGarage shelves run 16 to 24 in (41 to 61 cm) deep, and 24 in on both walls takes 4 ft off the parking width. Rack drops, load limits and the reach ceiling.
- Garage sizes: single, double and tripleA working single garage is 14 x 24 ft (4.3 x 7.3 m) and a working double 24 x 24 ft (7.3 x 7.3 m), because a car door needs 30 in (76 cm) that no plan shows.
- Workbench height, depth and clearancesA workbench is 34 in (86 cm) for heavy work, 39 in (99 cm) for assembly and 45 in (114 cm) for precision, all measured down from your own elbow height.
- Workshop tool clearances: saws, benches and infeedRipping a full sheet on a table saw needs 18 ft 6 in (5.6 m) of clear line, and a garage has exactly one. Mitre saw wings, dust ducts and mobile base heights.
Frequently asked questions#
What is the minimum size for a double garage?
Twenty by twenty feet (6.1 x 6.1 m) internally is the common builder minimum and it is about 6 in (15 cm) short of comfortable. Two vehicles measured over the mirrors at 78 in (198 cm) plus three 30 in (76 cm) gaps come to 20 ft 6 in (6.25 m). At 20 ft you park both cars or you open both front doors, and you choose which every time you arrive.
How deep does a garage need to be?
Twenty-two feet (6.7 m) of clear depth suits a car up to 16 ft (4.9 m) long and leaves 3 ft (91 cm) at the front for a bench or a bin and 3 ft behind to walk round. Full-size pickups run 19 to 21 ft (5.8 to 6.4 m), so a 20 ft garage will not close its door on one, which is the single most common sizing failure in North American plans.
How much headroom does a garage door need above the opening?
Twelve to 18 in (30 to 46 cm) between the top of the opening and the ceiling for a standard torsion-spring lift, and 14 in (36 cm) is the figure most installers want. Low-headroom track kits work down to about 4.5 in (11 cm) at a cost in smoothness. Add 2 in (5 cm) more if the opener rail passes over the door.
How high should a garage workbench be?
Thirty-four to 36 in (86 to 91 cm) for general assembly, which puts the surface just below a standing wrist. Drop to 32 in (81 cm) for planing, sawing and anything that needs body weight over the work, and rise to 38 to 40 in (97 to 102 cm) for close detail or soldering. Bench depth of 24 to 30 in (61 to 76 cm) keeps the back edge within reach.
How high should an EV charger be mounted?
Between 18 and 48 in (46 and 122 cm) from the floor to the charging connector is the usual working range indoors, and mounting near 48 in (122 cm) keeps the cable off a wet floor and inside a comfortable reach. Cables are 15 to 25 ft (4.6 to 7.6 m) long, so position the unit against where the car's port sits, not against where the consumer unit happens to be.
Can a garage floor be level with the house floor?
Yes, where the garage floor drains to the door and the code official accepts it. The IRC allows the landing at an exterior door to sit up to 7.75 in (197 mm) below the threshold only where the door does not swing out over that step. If the door swings towards the garage, the floor must be within 1.5 in (38 mm) of the threshold.
How deep should garage shelving be?
Sixteen to 24 in (41 to 61 cm). A 24 in shelf on both long walls removes 4 ft (1.2 m) from the parking width, which turns a 24 ft (7.3 m) double garage into a 20 ft one. Deep shelving belongs on the end wall in front of the cars, where the depth is spent on length nobody is using.
What ceiling height does a garage need?
Eight feet (2.44 m) is the minimum that takes a 7 ft (2.13 m) door and its track. Nine to 10 ft (2.7 to 3.0 m) makes overhead racks and an 8 ft door possible, and a four-post car lift wants 12 ft (3.66 m) clear. Ceiling height is the cheapest dimension to buy at the framing stage and the most expensive to add later.
Sources and standards referenced#
- International Residential Code International Code CouncilGarage to dwelling separation, door construction, landings and step heights
- Architects' Data Ernst Neufert, Wiley-BlackwellVehicle dimensions, parking bay sizes and manoeuvring space
- Time-Saver Standards for Building Types De Chiara and Callender, McGraw-HillGarage and parking layout dimensions, aisle and stall geometry
- National Electrical Code (NFPA 70), Article 625 National Fire Protection AssociationElectric vehicle supply equipment mounting heights and connector positions
- BS 8300-1: Design of an accessible and inclusive built environment British Standards InstitutionParking bay widths and the access zone beside a vehicle
We cite published codes, industry planning guidelines and manufacturer specifications. Where a figure is our own recommendation rather than a published standard, the text says so. See how we measure.