Towing Capacity 101: Tips & Tricks for Making Accurate Calculations

When it comes to determining the capacity of your towing setup (including any and all vehicles in your business's fleet), there are two terms you're likely to encounter: payload capacity and towing capacity. And while each term speaks to the total capacity of your vehicle in one sense or another, there's a very important difference between the two.

Towing capacity refers to the maximum weight your vehicle can pull behind it (in a safe and legal manner). This generally refers to the largest trailer size (by weight) that your vehicle can safely handle and will depend on a number of factors, from the type of vehicle you're driving to the towing setup you use to haul a trailer.

By contrast, payload capacity is a term used to describe the total weight that your vehicle can carry, including everything inside the vehicle cabin, from the driver to the backseat to any passengers and even what's in your glove box. In addition, your vehicle's payload capacity also includes cargo and items in the truck bed.

Towing capacity is higher than payload capacity. You can pull more behind you than you can carry in your vehicle.

To properly calculate your overall towing capacity, the first step is to determine your truck's gross combined vehicle weight rating (GCVWR) and curb weight. You can usually find the information you need in your vehicle's owner's manual. To calculate your truck’s towing capacity, subtract the curb weight from its GCVWR. (The GCVWR alone will give you the maximum weight of your loaded truck and trailer.)

Towing Capacity = Gross Combined Vehicle Weight - Curb Weight

When making calculations for towing capacity and trailer weight, you may want to familiarize yourself with the following terms that are commonly used in the industry.

Gross Vehicle Weight Rating (GVWR)

GVWR is the maximum weight a vehicle can hold while not in motion (sitting still).

Gross Combined Weight Rating (GCWR)

Not to be confused with the GVWR above, the GCWR or GCVWR is the maximum capacity of both your truck and trailer combined, including cargo.

Gross Axle Weight Rating (GAWR)

This refers to the maximum weight you can support per axle of your truck.

Gross Trailer Weight (GTW)

This is the actual combined weight of your trailer and cargo. It doesn't include the truck and isn't a capacity.

Tongue Weight (TW)

Tongue weight refers to the total weight or force being exerted on the trailer ball. The tongue weight may change as the vehicle is in motion. This is an important safety factor; if the tongue weight is too high, it can affect the rear tires of your vehicle.

Curb Weight

Curb weight is the total weight of the vehicle, including fluids (i.e., a full tank of gas) and essential equipment. Curb weight does not include passengers or cargo.

Dry Weight 

Dry weight refers to the weight of the vehicle without essential fluids (such as gasoline) and without passengers or cargo.

Payload Capacity

Payload capacity is the maximum weight your truck or vehicle can carry in the cabin and truck bed (not including any trailers).

1. Upgrade Your Hitch

The type of hitch you use (including its class) will help to determine your towing capacity. For example, you can tow more with a Class III hitch than a Class II hitch—even with the same truck—as long as the hitch is compatible with your towing vehicle. 

2. Install a Weight-Distribution Hitch

If you don't have a weight-distribution hitch, you can install one to further increase your towing capacity. These hitches use spring bars to level the load and reduce swaying motions, offering a fairly affordable option for increasing capacity.

3. Upgrade the Brakes

Upgrading to larger brake pads and rotors can also make a difference in your towing capacity, especially if your braking power is limiting your current setup.

4. Replace the Axles

Don't forget about your truck's axles, which also play an important role in towing capacity. If possible for your vehicle, you may be able to replace the standard axles with stronger axles that can handle larger loads.

5. Add a Bigger Radiator

Last but not least, a new and improved radiator can provide a much-needed boost to your engine’s cooling capacity, which can also help you increase your towing capacity without adding unnecessary wear and tear to your truck.

1. Install Bigger Wheels

Avoid adding bigger aftermarket wheels to your truck, which may look stronger but can also invalidate your calculated towing capacity due to the different demands they place on your vehicle. 

2. Change the Tires

Of course, you'll need to replace your tires from time to time, but when you do so, make sure the new tires are able to handle your towing setup and won't affect its total capacity. For example, you may be able to improve your gas mileage with different tires, but these can also end up negatively affecting your towing capacity.

Looking for more information on your specific vehicle and its towing capabilities? You'll find everything you need using Zoro's handy online tool, which can help you find the right hitches and towing products based on your vehicle's make, model, and year.

There are a number of related factors that can go into your towing capacity, and it's not always an easy calculation to make. Of course, you'll want to start with your vehicle and its stated capacity in the owner's manual. You may need to make a calculation using information such as the gross combined vehicle weight (GCVW) and curb weight. But you'll also want to consider the towing setup you're using in its totality. For example, while upgrading to a new hitch can increase your towing capacity, you can also bring it down inadvertently by switching to new tires or overtaxing your radiator.

Looking for towing products, hitches, and other accessories for hauling trailers? Look no further than Zoro.com's selection of thousands of products from the brands you know and trust.

Product Compliance and Suitability

The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness, or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand, and follow all manufacturer instructions.