What Is Tongue Weight and Why Is It Important?

One of the most important things you can do to keep your family and yourself safe while towing a trailer is making sure you know the various weights and weight limitations associated with your rig

When you’re traveling down the road hauling a travel trailer or a fifth-wheel or any other kind of open/enclosed trailer, various weights factor into your towing experience and, more importantly, your safety and the safety of everyone traveling the roads with you. Many people are well aware of what terms like GVWR (gross vehicle weight rating), dry weight, and tow capacity mean but the meaning of factors like tongue weight is not as well understood.

So, what is tongue weight and how might it impact your travel?

In today’s post I’ll answer those questions and more as we investigate the term tongue weight and the reason why it’s so critical to understand. If you ever plan to tow a trailer you’ll want to pay close attention because in order to tow safely, you’ll need to understand this important topic.

Fifth-wheel trailers at Rain Shadow RV Park neat Clarkdale, Arizona © Rex Vogel, all rights reserved

What is tongue weight?

Tongue weight is a term related to towing. Sometimes denoted as TW, it’s defined as the downward force that the tongue of a trailer applies to the hitch of the tow vehicle. In other words, the force the trailer tongue exerts on the hitch ball.

Improper tongue weight can be the difference between a safe towing experience and a very dangerous one.

The trailer is like a lever and the axle of the trailer is the pivot point (or fulcrum) for that lever. If too much or too little weight is applied to the tongue of the trailer, a dangerous situation can result (more on that in a minute). Tongue weight can’t be too heavy and it can’t be too light. It has to be just about right—balanced—like the weights of a couple of people on a seesaw at the playground.

Travel trailers at Creek Fire RV Resort, Savannah, Georgia © Rex Vogel, all rights reserved

Is tongue weight the same as hitch weight?

Yes. The terms tongue weight and hitch weight are interchangeable as both refer to the force a trailer exerts on a hitch.

Sometimes the term pin weight is used instead of either of the other terms but while pin weight refers to the very same concept it’s usually used in reference to fifth-wheel trailers specifically.

>> Related article: The Pros and Cons of Buying a Travel Trailer

Regardless, all three terms refer to the downward force the trailer/fifth-wheel applies to the hitch on the vehicle towing it.

Travel trailer at Whispering Hills RV Park, Georgetown, Kentucky © Rex Vogel, all rights reserved

How do you calculate tongue weight?

To calculate tongue weight you’ll take the weight of your tow vehicle alone and subtract it from the weight of your tow vehicle with the trailer attached. 

Weight of tow vehicle while trailer is connected–tow vehicle’s weight=tongue weight

If the result of your calculation is within the proper tongue weight range for your loaded trailer and the capacity of your hitch and tow vehicle, then your setup is properly balanced. If not, some adjustments need to be made.

At the end of this post, I’ll describe a few different ways to check the weight of your trailer’s tongue.

Trailers and a tow vehicle at A+ Motel and RV Park, Sulphur, Louisiana © Rex Vogel, all rights reserved

What is proper tongue weight?

Proper tongue weight for a trailer with a ball-mounted hitch is between 10 and 15 percent of the Gross Towing Weight of the trailer.

For example, the proper tongue weight for a trailer that weighs 1,000 pounds would be somewhere between 100 and 150 pounds.

Using a real-weight scenario if a 3,000-pound trailer is loaded with 1,000 pounds of cargo, the proper tongue weight of the loaded trailer should be somewhere between 400 and 600 pounds (between 10 percent and 15 percent of the 4,000 pound total).

There are some complexities to navigate here, however. For instance, fifth-wheel or gooseneck trailers are designed to handle significantly larger loads so proper TW for these trailers is generally agreed to be between 15 and 30 percent of the total loaded trailer weight.

Fifth-wheel trailer at Hacienda RV Resort, Las Cruces, New Mexico © Rex Vogel, all rights reserved

What happens if tongue weight is too heavy?

If the tongue is too heavy, the tow vehicle’s steering will be impacted. Traveling ahead of its axis, a too-heavy trailer tongue will also affect the way the trailer moves along the road and the way it stops.

When TW is too heavy, stress is placed on the frame, suspension, tires, drivetrain, or brakes of the vehicle being used to tow. Because of the excessive weight transferred through the hitch ball, the rear tires of the tow vehicle can become overloaded, pushing the rear end of the vehicle around.

>> Related article: RV Weight Distribution Tips for Packing your RV

A too-heavy tongue weight may also negatively impact vehicle handling especially when rounding curves and taking corners. This is due to the fact that the front of the tow vehicle is being lifted up, reducing the weight on the front tires and thus their grip and steering effectiveness. Moreover, the vehicle’s stopping distance may be impacted such that you’re unable to stop fast enough after depressing the brake pedal.

These are very dangerous situations owed to improper tongue weight. Fortunately, tongue weight can be adjusted relatively easily. If you’ve ever seen the rear of a vehicle in a low position while towing, what you were likely seeing was an improperly loaded trailer resulting in excessive tongue loading. In such a case, the load in the trailer would need to be adjusted so that more of the weight was moved toward the back, behind the trailer’s axle.

Trailers at Columbia River RV Park, Portland, Oregon © Rex Vogel, all rights reserved

What happens if tongue weight is too light?

If there is insufficient weight on a trailer tongue, the trailer may be difficult to control and may sway from side to side. If the tongue is too light, cargo needs to be moved forward of the trailer’s axle.

What happens with a too-light tongue weight is that the tongue of the trailer isn’t exerting sufficient downward force on the tow vehicle’s hitch ball. This leads to trailer sway, a very dangerous situation that puts the trailer at risk of slipping off the ball and disconnecting from the tow vehicle.

Fifth-wheel trailer at Edisto Beach State Park, South Carolina © Rex Vogel, all rights reserved

How to check your tongue weight?

There are a few different ways to check.

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The first method requires you to drive to a public scale or weigh station and follow these steps:

  • Load your trailer and the vehicle you’ll be towing it with exactly as they’ll be loaded for an upcoming trip (including food, fuel, water, and propane)
  • Drive onto the scale at the weigh station making sure all four wheels of the tow vehicle are on the scale while also making sure the wheels of the trailer are NOT on the scale
  • Make a note of the weight of the tow vehicle
  • Without moving the vehicle(s), unhook the trailer and jack up the trailer tongue so that there is no weight on the hitch ball
  • Make a note of the weight of the tow vehicle only (this is your GVW or gross vehicle weight of the tow vehicle)
  • Subtract the GVW from the weight of the tow vehicle with the trailer attached (this is your tongue weight)

The second way to check is to use a trailer tongue weight scale.

A scale with a 5,000-pound capacity would be appropriate for most fifth-wheels and goosenecks). Scales are also available with 1,000 and 2,000-pound capacities.

If you expect your tongue weight to be less than 300 pounds, you can use a bathroom scale. To do this, you’ll place the tongue or jack directly on the bathroom scale (or, you can place a small piece of plywood on the scale to protect it).

If you anticipate that the weight may be more than 300 pounds, you can use a special arrangement of boards and pipes to reduce the amount of weight being placed on the bathroom scale, multiplying it appropriately to calculate the actual weight. That method, complete with instructions and diagrams can be found on the Curt Manufacturing website.

Travel trailer at Cedar Pass Campground, Badlands National Park, South Dakota © Rex Vogel, all rights reserved

Why is tongue weight so important?

As I’ve noted throughout this article, tongue weight impacts the operation of the tow vehicle and the trailer. Improper tongue weight can have very serious consequences.

In the case of too much, the rear tires of the tow vehicle can be overloaded resulting in the rear end of the vehicle being out of control and reducing the tow vehicle’s ability to both steer and stop.

>> Related article: 6 Great Tips for RV Beginners

In the case of too little, extremely dangerous trailer sway can result even to the extent of the trailer being moved off the ball and disconnecting from the tow vehicle. This could easily lead to a horrible accident involving not only damage to your trailer but injury and loss of life.

So, tongue weight is extremely important—and fortunately, also easily adjusted.

Worth Pondering…

Speed was high

Weather was hot

Tires were thin

X marks the spot

—Burma Shave sign