Most homeowners need at least a 12×20 metal garage for a single vehicle with basic storage, 20×20 for a two-car garage, and 24×30 or larger for trucks, extra storage, or a workshop combination. The right size ultimately comes down to what you’re parking, what else you need to store, and how much room you want for movement around the vehicle.

Sizing a building correctly the first time matters — it’s far more cost-effective to size up slightly during design than to outgrow your space within a year or two. Our Build & Price tool lets you build your Custom Metal Garage at any width or length we offer, so you can compare dimensions and pricing side-by-side before you order.

How Do I Size a Metal Garage for My Vehicle?

Start with your vehicle’s actual dimensions, not just its class. A standard sedan needs roughly 12×20 feet of space to fit comfortably with room to open doors and walk around it. Full-size trucks and SUVs typically need at least 14×25, and if you’re housing a work van or towing a trailer, 16×30 or wider gives you the clearance to maneuver without scraping mirrors or door panels.

What Size Do I Need for Two or More Vehicles?

A two-car metal garage generally starts at 20×20 feet, though 24×24 or 24×30 gives noticeably more breathing room for full-size vehicles, storage shelving, or a workbench along one wall. If you’re parking three vehicles or mixing cars with a boat or ATV, 30×40 and larger clear-span layouts are worth exploring since they eliminate interior support columns that can get in the way.

Does Storage or Workshop Space Change the Sizing?

Yes — and this is where most people undersize their building. If you want workbench space, shelving, or room for lawn equipment in addition to vehicle parking, add at least 8-10 feet of length or width beyond your vehicle-only measurement. Many customers find that combining a garage with an attached shed area, or opting for a slightly larger clear-span structure, gives them flexibility as storage needs grow over time.

What About RVs or Larger Equipment?

RVs require significantly more room than standard vehicles, both in length and especially in height. If you’re storing anything RV-sized, it’s worth reviewing our complete guide to RV garage dimensions, which breaks down sizing by RV class, or exploring our dedicated RV carport options built specifically for larger vehicles.americansteelinc

Should I Size Up for Future Needs?

Almost always, yes. Sizing a metal garage 20-25% larger than your current need is a common recommendation, since it accommodates a second vehicle, added storage, or a workshop down the road without requiring a whole new structure. It’s a much smaller cost difference upfront than building a second structure later.

Get the Right Size for Your Property

The best way to lock in the right dimensions is to configure them directly — try different widths and lengths in our Build & Price tool and see the price update instantly, or schedule a consultation with our team to talk through your vehicle count, storage needs, and property layout before you finalize a size.

FAQ

What’s the minimum size for a single-car metal garage?

12×20 feet is the common minimum for one vehicle with a bit of extra room, though 12×21 or 14×21 gives more comfortable clearance for larger sedans or trucks.

How much extra space should I add for storage?

Plan for at least 8-10 additional feet in length or width if you want shelving, a workbench, or room for lawn equipment alongside your vehicle.

Do I need a permit based on garage size?

Many jurisdictions require permits once a structure exceeds a certain square footage, so check your local building department early in the planning process — this can also affect setback requirements from property lines.

Can I customize the size beyond standard dimensions?

Yes — our buildings are fully customizable in width, length, and height, so you’re not limited to a fixed set of sizes when configuring your structure online or with our team.