How To Determine the Weight Capacity of a Flat-Bed Trailer

Updated 04/15/2019 | Published 04/12/2019

Question:

HOW MUCH WEIGHT CAN A DUAL AXLE AND A TRIPLE AXLE ACCOMODATE ON A FLATBED

asked by: Kim C

Expert Reply:

The payload capacity of a trailer will take into account several variables such as frame strength, axle capacity, tire capacity etc. so I cannot provide an exact payload capacity for all dual/triple axle trailers. The only way to do this for a trailer is to find the gross vehicle weight rating (GVWR) which is the most a trailer can weigh. This will take into consideration both the weight of the trailer and how much payload you have. Therefore, if you know your GVWR you can subtract the weight of the trailer to find your payload capacity. If you are building a trailer yourself then things will get a bit more complicated but there are specialists available who's job is to help calculate the GVWR of a trailer.

As a very rough estimate, you can add the weight capacity of all your trailer axles and then another 10-15% for the tongue weight to give you a rough GVWR. For example, if you have two 7,000 lb trailer axles like part # 8327834 then your GVWR is likely around 15,000 - 16,000 lbs. If you don't know what your axle capacity is then you can either look for the tag or measure the diameter. If it is 2-3/8" diameter then you likely have 3,500 lb axles whereas if it is 3" diameter it could be anywhere from 5,200-7,000 lbs.

expert reply by: Conner L