What size metal garage do I need for two cars?

A 20x20 metal garage may fit two compact vehicles tightly, but many customers prefer a 24x25 or 24x30 metal garage for better door clearance, walking space, and basic storage. Larger trucks, shelves, and workbench space may require 24x35, 24x40, or 30x40.

What size steel building is best for a workshop?

A small workshop may start around 24x30, while a more comfortable garage and workshop combination is often 30x40 or larger. The best size depends on vehicles, tools, benches, storage, equipment, and how much open workspace is needed.

What size metal building do I need for an RV?

An RV cover or enclosed RV building should be sized around the actual RV length, width, and total height including roof AC units, vents, racks, and antennas. Many RV covers require taller legs and extra length for safe clearance.

Should I choose a larger metal building size?

If the larger size fits your property and budget, sizing up is often more useful long-term. Extra room can help with storage, door swing, toolboxes, workbenches, equipment, and future needs.

Can I use this metal building size calculator as my final building plan?

No. This calculator is for general planning only. Final building size should be confirmed based on actual vehicle measurements, property layout, local setbacks, foundation requirements, door placement, building height, roof style, and permit requirements.

Metal Building Size Calculator

Trying to figure out what size metal garage, carport, RV cover, workshop, barn, or steel building you need? Use this free size calculator to get a practical starting recommendation based on your vehicles, equipment, storage needs, workspace plans, and future expansion goals.

This tool is designed to help you think through real-world space, not just square footage. It can help you avoid choosing a building that feels too tight after vehicles, doors, shelves, tools, or equipment are added.

Call 844-867-6385 Request a Custom Quote

Find the Right Size Before You Order

Choosing a steel building size is one of the most important decisions in the buying process. A 20x20 garage may technically fit two small vehicles, but it may feel tight once you account for door swing, walking space, storage shelves, mowers, ATVs, tools, workbenches, or larger trucks. A 24x30, 30x40, or 40x60 may be a better long-term choice depending on how you plan to use the building.

The calculator below gives a planning recommendation only. Final building size should be confirmed based on your property layout, local setbacks, vehicle dimensions, door placement, roof style, height needs, and budget.

Free Metal Building Size Calculator

Answer a few simple questions and get a suggested starting size, a better long-term size, leg height guidance, door recommendations, and a copyable quote summary.

Primary Building Use Select the closest match for how you plan to use the structure.

Space Preference Most customers are happier long-term with a comfortable or roomy fit.

Standard Cars Sedans, compact cars, small crossovers.

Trucks / SUVs Pickup trucks, large SUVs, work vehicles.

Motorcycles / ATVs Motorcycles, ATVs, small side-by-sides.

Large Items Tractors, boats, large mowers, UTVs, compact equipment.

RV / Camper / Boat Length Choose the closest total length, including hitch or rear storage if needed.

Tall Vehicle / RV Height Include roof AC units, racks, vents, or antennas if applicable.

Workshop / Workbench Space Adds room for tools, benches, and working around vehicles.

Storage / Shelving Needs Storage takes up usable floor space faster than most people expect.

Building Style Enclosed buildings usually need more planning for doors and clearances.

Door Preference Door layout can affect the best width and length.

Important: This calculator provides a planning recommendation only. Always confirm final building size, vehicle measurements, local setbacks, door placement, roof style, height, anchoring, foundation needs, and permit requirements before ordering.

Suggested Starting Size

24x30

A practical starting size for two standard vehicles with basic walking room.

Garage 2 Vehicles Comfortable Fit

Better Long-Term Size

30x40

Consider sizing up if you want storage, a workbench, larger vehicles, or future flexibility.

Recommended Leg Height Range

9 ft - 10 ft

Typical planning range for enclosed garages with standard vehicles. Taller vehicles, RVs, lifts, or equipment may need more height.

Door & Layout Suggestions

Two 9x8 or 10x8 roll-up doors are common for many two-vehicle garages. Larger trucks may benefit from wider or taller doors.

Planning Notes

Leave room for door swing, walking space, shelves, workbenches, and future storage. A slightly larger building is often more useful long-term.

Metal Building Size Planning Summary: Primary use: Metal Garage Suggested starting size: 24x30 Better long-term size: 30x40 Recommended leg height range: 9 ft - 10 ft Notes: This recommendation is for planning only. Confirm final dimensions, door layout, height, foundation, setbacks, and local permit requirements before ordering.

Common Metal Building Sizes and What They Are Used For

Every property is different, but these common building sizes can help you compare the calculator recommendation against typical real-world uses. When in doubt, think beyond what you need today and consider how the building may be used several years from now.

Building Size	Common Uses	Best For
12x20	Single car, small storage, compact cover	Budget-friendly one-car protection
18x20 / 20x20	Two compact vehicles, small carport, basic garage	Tighter two-vehicle layouts
20x25 / 22x25	Two vehicles with better depth	Cars, small trucks, basic storage
24x30	Two vehicles, walking room, small storage	Popular residential metal garage size
24x35 / 24x40	Two vehicles plus mower, ATV, shelves, or workbench	Residential garages with storage
30x40	Trucks, workbench, storage, small shop layout	Garage and workshop combinations
30x50 / 30x60	Multiple vehicles, equipment, business storage	Workshops, farm storage, larger garages
40x60+	Commercial storage, farm equipment, fleet storage, larger shops	Business, agricultural, and commercial use

How to Choose the Right Metal Garage or Steel Building Size

The best steel building size depends on more than the number of vehicles you want to park. You should think about how the building will be used every day, how often you need to open vehicle doors, whether you want storage shelves, whether you need a workbench, and whether the building may need to hold more equipment in the future.

Plan for Door Clearance

A vehicle may fit on paper, but you still need space to open doors, walk around, unload groceries, access tools, and move safely between vehicles.

Add Storage Space

Shelving, mowers, bikes, toolboxes, freezers, ATVs, and seasonal items can quickly use up the extra space in a garage or workshop.

Think About Height

Trucks, RVs, boats, lifts, tractors, and equipment may need more leg height, taller doors, and more clearance than standard vehicles.

Consider Side Entry

Side-entry garages can be convenient on wider buildings, but they may require more driveway space and a different property layout.

Leave Room to Grow

Many customers wish they had gone larger after adding tools, storage, equipment, or another vehicle. Future flexibility can be valuable.

Check Local Setbacks

Property lines, easements, septic areas, driveways, and zoning setbacks can limit the size or placement of your building.

Metal Building Size Planning Checklist

Before finalizing your metal building size, walk through these planning points. This can help you avoid choosing a building that is too small, too low, or difficult to use after installation.

Measure the actual length, width, and height of your vehicles, RV, boat, trailer, tractor, or equipment.
Add room for door swing, mirrors, hitches, ramps, toolboxes, and walking clearance.
Decide whether you want open sides, partial enclosure, or a fully enclosed building.
Think about whether you need front-entry, side-entry, or drive-through roll-up doors.
Plan where shelves, workbenches, freezers, lawn equipment, or business inventory will go.
Consider whether your needs may grow over the next five to ten years.
Check property setbacks, local permits, HOA rules, drainage, and site access.
Confirm whether you need concrete, gravel, asphalt, or ground installation based on the building type.

Helpful tip: If you are torn between two sizes and the larger size fits your property and budget, the larger option is often more practical long-term.

Helpful Steel Building Planning Resources

After you have a better idea of the size you need, use these resources to plan the foundation, site prep, permits, roof style, and building options.

Steel Building Concrete Pad Calculator Concrete Requirements for Steel Buildings Preparing Your Site for a Steel Building Guide to Pulling Your Permit Roof Styles Explained 12 Gauge vs 14 Gauge Steel Buildings Metal Garages Commercial Steel Buildings

Ready to Price the Right Size Steel Building?

Once you have a general size in mind, Johnson Carports and Garages can help you price a custom metal garage, carport, RV cover, workshop, barn, or commercial steel building delivered and installed.

Call 844-867-6385 Get a Free Quote