How to calculate axle weight
Before you get on the road with a trailer, you need to be sure that your trailer can handle the load you are going to be hauling.
Each state has a series of regulations that govern the amount of weight that can be hauled with a trailer, and every trailer comes with a rating for a total, or gross, amount of weight it can carry. If you overload your trailer, you can not only wind up with an expensive ticket, but you could also have a serious accident. You can quickly estimate the axle weight of your load, tractor or pickup, and your trailer, to determine if you can safely transport the cargo with your equipment.
Add the total weight of the load you will be carrying to the total trailer weight.
Divide the total weight of the load and trailer by the total number of tandem axles. Include the load bearing axle in your count. The load bearing axle is the axle that is part of the tractor or pickup you are using to pull the load that is closest to the trailer. This amount represents the total weight per tandem axle of your load and trailer.
Write down the total weight of your tractor or pickup. This weight is usually listed on the interior of the driver's side door as the GVW (gross vehicle weight). Seventy per cent of your GVW is the weight of the steering axle--the axle located at the front of your tractor or pickup. Divide the remaining 30 per cent of your GVW by the number of axles you used in Step 2.
Add the weight of the load and trailer per axle to the weight of your tractor or pickup per axle together. The sum will give you the total estimated axle weight.
- Do not forget to list the total axle weight of your steering axle that you found in Step 3 along with your final weights found in step 4 when trying to determine the capacity of your tractor and trailer.
- This equation provides an estimate for the total axle weight of load, tractor and trailer only. Automated software is available to perform precise calculations that take into account air inflation, distance of axles and road conditions that are necessary to determining the behaviour of a load in transit.
- Michael Jeffcoat