How Is Towing Capacity Calculated?

Towing capacity is the maximum towing load of a towing vehicle to be towed by another towing vehicle. The towing vehicle’s towing capability is determined by many factors including engine power, torque, transmission type (manual or automatic), wheelbase and suspension system. Towing capacity can also depend on whether you are towing up an incline, a decline or towing to the rear of the towing vehicle.

In order to determine towing capacity you must find the towing specification provided by either your towing manual or from your dealer. You can then calculate towing capacity as follows:

  • GVWR – Tow Capacity = Max Tow Capacity
  • Unloaded Vehicle Weight – Max Tow Capacity = Tow Capacity to nearest 10 lbs.
If towing to the rear, this calculation is to be used in place of vehicle weight.
  • GVWR – Unhook Weight = Max Unloaded Trailer Weight to nearest 100 lbs.
    • This calculation should only be used when towing to the rear of your towing vehicle to determine the maximum weight to be towed.
Both towing to the rear and towing to the front of your towing vehicle take into account the tongue weight or king pin weight. You can calculate tongue weight as follows:
  • Unloaded Vehicle Weight – Hitch TW = Tongue Weight to nearest 100 lbs.
  • Unloaded Vehicle Weight – Trailer TW = Tongue Weight to nearest 100 lbs.
  • Unloaded Vehicle Weight – Kingpin TW = Tongue Weight to nearest 100 lbs.
The towing capacity of a towing vehicle with a weight distributing hitch is equal to or greater than that towing to the rear of your towing car. The towing capacity of a towing vehicle to the front is equal to or greater than towing to the rear by adding the following to your towing capacity to determine maximum front tow capacity:
  • Ft TW = Tow Capacity + (GVW – Hitch TW)

By following these simple towing capacity calculations, you can ensure that towing your tow car to its destination will be safe. If you are unsure of your towing capabilities, it is suggested to arrange roadside assistance to remove your towing vehicle from the roadway to a location where towing can be done safely.

Roadside Assistance is offered through many auto insurance companies and is included in some car insurance policies with no additional cost to the policyholder. When you have roadside assistance, they will provide towing to a repair facility of your choice to have your towing vehicle repaired.

Chris Turn

Chris Turn