Trailer size is the decision buyers most often regret, whether they went too small and ran out of room or went too big and found themselves with something awkward to tow and store. There is a practical way to get it right. The six methods below are the same ones the team at Grizzly Trailer Sales uses when helping customers choose between a 6×10, a 7×16, or something larger. Five southern Idaho places to shop follow the list.
How do you figure out what size trailer you need?
1. Measure your largest item and add working room
Start by measuring the widest and longest thing you plan to haul, then add space to walk around it and strap it down. Measure the usable width between the fenders, not the overall trailer width. Common utility deck widths include 60, 77, and 83 inches, and full-size side-by-sides often need the 77- or 83-inch decks. Leave at least a few inches on each side so you can reach tie-down points without climbing over the load.
2. Weigh your heaviest load instead of guessing
Look up your machine’s dry weight on the manufacturer’s spec sheet, then add fuel, attachments, and gear. For loose materials, use the supplier’s weight per yard; a cubic yard of gravel or topsoil is heavier than most people expect. If you’re unsure, run your loaded truck across a certified truck stop scale for a small fee. The total needs to fit within the trailer’s payload, which is its GVWR (gross vehicle weight rating, the most it can safely weigh loaded) minus its empty weight.
3. Work backward from your tow vehicle
Your truck sets the upper limit for trailer size. Check the towing capacity in the owner’s manual and the payload figure on the sticker inside the driver’s door jamb. Tongue weight usually runs 10 to 15 percent of the loaded trailer’s weight, and it counts against that payload. A 7,000-pound GVWR trailer loaded to capacity can put 700 to 1,050 pounds on the hitch, which is more than some half-ton pickups can handle once the cab is full.
4. Choose a length that lets you balance the load
A common loading guideline puts about 60 percent of the cargo’s weight ahead of the axle. That usually means your trailer needs to be several feet longer than the item you’re hauling so you can position it correctly. Rough starting points:
- 10 to 12 feet for mowers, yard equipment, or a single ATV
- 14 to 16 feet for most side-by-sides or two ATVs
- 18 to 20 feet for cars and compact equipment
5. Let the weight decide between single and tandem axles
Single-axle utility trailers are typically rated up to about 3,500 pounds GVWR. Tandem-axle trailers built with two 3,500-pound axles reach 7,000 pounds, and equipment trailers with heavier axles go well beyond that. Brakes also factor in here. Idaho requires brakes on trailers with an unladen weight of 1,500 pounds or more, which covers most tandem-axle trailers. If your heaviest load is anywhere near 2,500 pounds, a tandem axle gives you room to grow.
6. Check where the trailer will live and travel
Measure your driveway, gate, side yard, or garage before you buy. Standard residential garage doors are often 8 or 9 feet wide and 7 feet tall, which rules out many enclosed trailers. Think about whether you’ll need to move the trailer by hand; an empty 6×10 is manageable, while a 16-foot tandem usually isn’t. Idaho Code 49-1010 sets legal vehicle dimensions, including a maximum width of 8.5 feet on highways without a permit.
Where can you compare trailer sizes in southern Idaho?
- Grizzly Trailer Sales
- Land Creek Auto & RV
- Xtreme RV
- Southern Idaho RV & Marine
- Ross Manufacturing & Repairs
1. Grizzly Trailer Sales
Grizzly Trailer Sales is run by Trell Whitehead and Matt Hope and has yards in Rupert and Montpelier. It’s a practical place to compare sizes in person, since each lot carries a range from compact single-axle utility trailers to tandem-axle, tilt, dump, enclosed, car hauler, and gooseneck models. When this article was written, listed prices included a new 6×10 Dutton utility trailer at around $2,150, a 16-foot tandem-axle utility at around $3,600, and an 18-foot Snake River tilt trailer at around $9,250. Bring your measurements and weights, and you can compare the options side by side. Used inventory is also available, financing can be started online, and Saturday visits are available by appointment.
2. Land Creek Auto & RV
Land Creek Auto & RV is an RV service business in Rupert.
3. Xtreme RV
Xtreme RV is an RV dealer in Eden.
4. Southern Idaho RV & Marine
Southern Idaho RV & Marine is an RV and boat dealer in Jerome.
5. Ross Manufacturing & Repairs
Ross Manufacturing & Repairs is a manufacturing and repair shop in Burley.
Getting the size right the first time
The right trailer size comes from five numbers: your largest item’s dimensions, your heaviest load, your truck’s towing capacity, its payload, and the space where the trailer will be stored. Write them down before you shop, and add some margin for the equipment you’re likely to buy in the next few years. A trailer sized that way stays useful long after the first load.
When you have your numbers, visit Grizzly Trailer Sales in Rupert or Montpelier to compare trailer sizes in person.
