The most common regret we hear is “I wish I had gone bigger.” The second most common is buying a building that fits the truck but leaves no room to open the doors. This guide is here to help you avoid both.
Steel building sizes are listed width by length. A 24×30 is 24 feet wide and 30 feet long. Ask us how length is measured on your quote, since roof and frame lengths can differ slightly.
Start With Rough Vehicle Sizes
These are general, rounded numbers. Always measure your own vehicles and equipment, including mirrors, racks, and anything on the roof.
- Compact or midsize car: about 6 feet wide and 15 to 16 feet long
- Full-size pickup: about 7 feet wide (more with mirrors) and 18 to 21 feet long, depending on cab and bed
- Side-by-side or UTV: about 5 feet wide and 10 to 12 feet long
- Bass or fishing boat on a trailer: often 20 feet or more overall with the tongue
- Compact tractor with loader: varies a lot, so measure length with the bucket on
What Fits in Common Sizes
| Size | Good For | Notes |
|---|---|---|
| 12×20 | One small car, mower and tools, or general storage | Tight for a full-size truck. Great as a storage shed. |
| 18×21 | One vehicle plus storage, or two small cars side by side | Two cars fit, but door-opening room is limited. |
| 20×20 | Two cars, or one truck plus a workbench area | A solid starter two-car garage. |
| 24×25 | Two vehicles with walking room, or one vehicle and a real work area | Extra width makes a big difference in daily use. |
| 24×30 | Two full-size trucks, or two vehicles plus storage or a bench | Popular size for a garage that doubles as a shop. |
| 30×40 | Three vehicles, a boat, or a workshop with room for parking | Good shop size with space for tools and projects. |
| 40×60 | Equipment, multiple vehicles, a boat and RV, or a commercial shop | Plenty of space for farm, contractor, or business use. |
These are starting points. Your layout, door placement, and how much stuff you have will change the answer.
Clearance Tips
Door Width
Your roll-up door should be wider than the vehicle, with room for mirrors and for not having to aim perfectly every time. A few extra feet of door width makes parking much easier, especially when backing in a trailer.
Door Height
Measure the tallest point of what is going in. For trucks, include racks and lights. For campers, include the A/C unit and antenna. For boats, include the windshield or tower on the trailer. Then leave room to spare. Remember that door height is limited by leg height (the wall height).
Walking Room
Plan for about 3 feet of space around each vehicle so you can open doors, carry things, and walk past without squeezing. That is often what makes a 24-foot-wide building feel so much better than a 20-foot one.
Workbench Space
A workbench and tool chests take more room than people think, maybe 2 to 3 feet deep plus room to stand. If you want a shop area, add that depth to your plan.
Future Plans
Will you buy a bigger truck, a boat, or a tractor in the next few years? Building a little bigger now is almost always cheaper and easier than adding on later.
Check Your Site, Too
The building also has to fit your land. Check setbacks from property lines, slope, septic and well locations, and room for the delivery truck to get in. Our site prep checklist walks through it.
Still Not Sure?
Our calculators can help you rough out space. When you are ready, use the quote builder or call or text 276-235-1191. Tell us what you want to fit inside, and we will help you pick the right size.
Common Questions
What size metal building do I need for two cars?
A 20×20 fits two cars, but a 24×25 or 24×30 gives you room to open doors and walk around comfortably. Measure your vehicles and plan for walking room.
How much walking room should I leave around a vehicle?
About 3 feet around each vehicle is a good rule of thumb so you can open doors and move past without squeezing.
How tall should my roll-up door be?
Measure the tallest point of what goes inside, including racks, A/C units, or boat towers, and leave room to spare. Door height depends on the building’s leg height.
Is it better to go bigger?
Most people wish they had. Building a little bigger up front is usually easier and cheaper than adding on later.
Ready to price your building?
Call or text 276-235-1191, or send us the size, location and what it is for. We will come back with a real number.