How Do I Know What Size Enclosed Cargo Trailer I Need?

How Do I Know What Size Enclosed Cargo Trailer I Need?

Choosing an enclosed trailer is more than picking a price—it’s about selecting the right size for safety, efficiency, and long-term value. A trailer that’s too small leads to cramped, inefficient trips and potential cargo damage. Too large, and it becomes hard to tow, store, and maintain.

Why Size Matters: Safety, Efficiency, and Cost

Trailer size affects your tow vehicle’s performance and your overall hauling safety. Overloading strains brakes and engines, while a correctly sized trailer distributes weight properly. A well-sized trailer improves fuel efficiency, reduces vehicle wear, and keeps ownership costs reasonable—from purchase price to insurance and maintenance.

How This Guide Helps

We’ll walk through key factors for picking the right trailer: understanding dimensions, matching them to your hauling needs, and ensuring compatibility with your tow vehicle.

Understanding Trailer Dimensions

When a trailer is listed as “6×12,” that’s the interior width by length. Actual usable space is affected by walls, wheel wells, and interior features. Always check both interior (cargo space) and exterior (overall footprint including tongue, hitch, tires, and fenders) measurements to ensure it fits storage areas and job sites.

Cubic Feet Matter

Length and width tell part of the story; interior height determines true cargo volume. Taller trailers can carry more without expanding the footprint, making them more versatile for bulky or stackable items.

Common Trailer Sizes

• 5′ Wide: Light-duty hauling, motorcycles, or hobbyist needs
• 6′ Wide: Popular for landscapers, contractors, and general utility use
• 7′ Wide: More room for UTVs or mobile business setups.
• 8.5′ Wide: Heavy-duty use like enclosed car trailers or large mobile operations. Standard for serious hauling.

Usage Patterns: Frequency and Distance

Occasional local trips may only need a small single axle trailer. Frequent or long-distance hauling benefits from tandem axles for stability, payload capacity, and highway safety.

Step 1: Define Your Hauling Needs

Consider your cargo type: tools, vehicles, mobile business equipment. Measure the largest items and plan your layout. Then, set a realistic budget, accounting for purchase, insurance, registration, and maintenance. Larger, feature-rich trailers cost more upfront and in upkeep. (However, higher-end trailers can also last longer. Check for warranties as well.)

Step 2: Match Size to Applications

• Small Trailers (4×6, 5×8, 6×10): Ideal for motorcycles, camping gear, or tools; lightweight and easy to tow.
• Mid-Size Trailers (6×12, 7×14, 7×16): Workhorses for landscapers, contractors, or mobile businesses; tandem axles enhance stability.
• Large Trailers (8.5×18 to 8.5×32): For cars, race teams, or large-scale operations; heavy-duty axles and brakes are standard.

Step 3: Key Technical Specs

• Weight Ratings:
  • Trailer Weight: Empty trailer weight.
  • GVWR: Max safe total weight including cargo.
  • Payload Capacity: GVWR minus trailer weight. Never exceed this limit. And it’s a good idea to stay below 80% of payload capacity in case the load bounces. Save yourself a broken axle or losing control of the trailer on the highway.
• Axle Configuration:
  • Single Axle: Lighter trailers, easier to maneuver, lower capacity.
  • Tandem Axles: Distributes load, improves stability, essential for heavy cargo.
• Tow Vehicle Capacity: Ensure your vehicle’s towing limit exceeds the trailer’s GVWR.
• Braking Systems: Electric brakes are required for heavier trailers to maintain control and comply with regulations.

Step 4: Loading and Volume Considerations

• Interior Height: Standard is 6' to 6' 6"; taller heights allow hauling large equipment or standing inside.
• Access:
  • Rear Ramp Doors: For vehicles or rolling equipment.
  • Barn Doors: Ideal for forklifts or tight rear access.
  • Side Doors: Convenient for quick access to front cargo.

Bonus Level: Skins

The skin is the thin metal shell outside the trailer. The thicker the skin, the better it will look in 5-10 years. 

• For enclosed trailers this means a thicker skin, ideally .030 skin or greater. Thinner skins will warp and eventually tear over time (see our video here). And trailer skins held on with high-quality epoxy will last longer than those riveted on—the rivets cause more warping and tearing.

Selecting the right enclosed trailer starts with understanding your cargo, frequency of use, and towing limits. Consider dimensions, payload, axle type, and practical features to ensure safety, efficiency, and long-term value. With careful planning, you’ll find a trailer that reliably supports your work or hobbies for years to come.