Pontoon Trailer Capacity

Trailer capacity is easy to figure, but different manufacturers rate their pontoon trailer capacity in different (often inaccurate) ways. Capacity is limited by the strength of the axles; the strength or rating on the spindles and hubs and then by the rating of the tires. A trailer with a #3500 axle can carry #3500., but the actual carrying capacity may be lower because of the rating of the tires. If the tires have a capacity of only #1300 (each) the pontoon trailer capacity is reduced to the lower capacity of the tires. (for a single axle trailer-#2600). There are other considerations, the strength of the frame and bunks, but these factors are difficult to determine. It’s easy to learn the true capacity of trailers. Check the rating, stamped on the axle and read the side wall of the tires. Some pontoon trailer manufacturers overate their trailers capacity. It’s a common practice to add #250-#300 to the capacity because that could be the amount of tongue weight on the hitch and it might eliminate weight on the trailer. We don’t use that method. Our trailers have sufficient capacity that we don’t have to add factors that may or may not be accurate.

Carrying Capacity

Once you know the capacity of the pontoon trailer, you can arrive at the carrying capacity. This is the figure that you should be most concerned with and again, is sometimes difficult to determine. The carrying capacity is arrived at by deducting the weight of the trailer from the lowest capacity of the axle or tires. Our PT-20/13 single axle pontoon trailer has a #3500 capacity axle but the tires limit the capacity to #3320. The trailer itself weighs #700 (the weight is on title), thus there is #2520 of capacity left to carry a pontoon boat.

PMI Trailer components
Axles on all PMI brand trailers have a #3500 capacity
(our) Single Axle Light Duty trailers have 12" D range tires with a capacity of #1250*
Single Axle trailers have 13” D range tires with a capacity of #1610*
Tandem Axle trailers have 13” C range tires with a capacity of #1360

Want to increase capacity on a tandem, specify D range tires
* we buy tires from different manufacturers, ratings can vary up to 6% from brand to brand


#1045 tires on a single axle pontoon trailer weighing #700 can carry a pontoon boat that weighs up to #1390.
  #1610 tires on a single axle pontoon trailer weighing #700 can carry a pontoon boat that weighs up to #2520.  On a tandem axle trailer, weighing #1000 with these tires you could carry #5440
Different pontoon trailer manufacturers calculate the capacity of their trailer in creative ways.  If you want to know the capacity, look at the tires and check the weight of the trailer (on the MSO)

Why should I care about overloading a pontoon trailer?

If you're not going very far and using your pontoon trailer infrequently you can probably get by with an overloaded trailer. It will wear the tires, burn up the bearings and the seals, but if you don’t use it much, failure will probably be the second owners problem. However if you tow frequently, tires will overheat and wear prematurely. Bearings will overheat and grease will dissipate more quickly than normal. The bearings will fail potentially scoring the axle and leading to a costly repair. This usually happens on the second day of your vacation and you will be broken down a hundred miles from home. (only kidding, but you get the point)

Loading Capacity

These two photos below illustrate the potential for overloading a trailer. It’s the same pontoon boat in both photos, it weighs about #4500. The tandem axle trailer on the left has the springs compressed almost to the point where the tires could rub the fenders. (about 1” away) The triple axle (#6000 capacity) trailer could care less about the #4500 load, the tires are 3” from the fenders.


Safely loaded pontoon trailer

When you take delivery of your new boat on a pontoon trailer, check the distance between the tires and the fenders. It should be 3”, if it’s less you may be overloaded.

For Information Call

(877)294-3395 or (574)294-3386