Trailer Tongue Weight: How to Measure & Calculate It

How Tos & Tips

One of the most important things you can do to keep your family and yourself safe while towing a travel trailer is making sure you know the various important weights and weight limitations associated with your rig. Making sure your tow vehicle and hitch can handle the trailer you choose will help ensure you have full control of the trailer even on rough roads, while stopping, and while going downhill.

Obviously, you will need to know the weight of your RV as a whole. However, this isn’t the only weight you need to know; the tongue weight is also incredibly important. In today’s article, we will focus on tongue weight so you can have a complete understanding of what it is, why it’s important, and how to find it.

What is Tongue Weight?

You may be wondering, “What is tongue weight?” This is an excellent question, and exactly what we will focus on in this section.

The term “tongue weight” might seem like a silly one. After all, who’s measuring the weight of their tongue? However, this weight actually has nothing to do with your tongue and everything to do with towing your trailer safely. For this reason, it’s something you should definitely educate yourself on.

Essentially, trailer tongue weight is the downward force the tongue of your trailer puts on the hitch of your tow vehicle. This force can be adjusted, and should be checked and adjusted regularly in order to keep it in the correct range.

Why should you keep your trailer tongue weight in check? Because a trailer tongue weight that is too heavy can make steering the tow vehicle nearly impossible. Meanwhile, a trailer that puts too little force on the tow vehicle hitch is likely to have problems with swaying.

Hitch Weight vs Tongue Weight

While researching important trailer weights and trying to get your rig set up safely, you may run across the term “hitch weight”. This leaves many people thinking about hitch weight vs tongue weight, and wondering what hitch weight even is and how it’s different from tongue weight.

The answer? It’s no different at all! Tongue weight and hitch weight are both terms that refer to the force a bumper pull trailer puts on a hitch.

When discussing fifth wheel trailers, the term “pin weight” also describes this very same thing, making things even more confusing for those who are just learning the ropes.

How to Measure Tongue Weight

Now that you understand what trailer tongue weight is, how important it can be, and the various terms for this weight, you may be wondering how to measure tongue weight so you can start setting up your trailer and tow vehicle to hit the road.

Fortunately, getting this measurement is fairly straightforward. It can be done using one of two tools: a simple bathroom scale, or a tongue weight scale designed specifically for this task—or, you can head to a commercial weighing station to get the job done.

Tongue Weight Scale

First, make sure your RV is loaded with everything you normally camp with, and park your vehicle and trailer on a hard level surface, such as a parking lot or driveway.

Place a tongue weight scale under the tongue jack and lower the jack until it is pressing on the scale, without the trailer being pushed taller than where it normally sits while being towed.

Without lowering any other jacks, detach your trailer from the truck and read the scale. This is your tongue weight. Pretty simple, right?

Bathroom Scale

Wondering how to determine tongue weight using a bathroom scale? It’s a bit more involved of a process, but we’ll explain it as best we can. NOTE: We recommend this method only for a trailer that is 3,000 lbs or lighter.

Again, make sure your trailer is fully loaded and parked on a firm, flat surface. Place a brick on the ground to the side of the coupler, about one foot away, perpendicular to the trailer (so, left to right). Place a bathroom scale down on the opposite side of the tongue from the brick, this time two feet away from the coupler. Make sure the brick and the scale are about the same height (use a different brick or stack things to make them even).

Place one length of pipe on the brick and another on the bathroom scale, both oriented in the same direction as the trailer (so, front to back). Then, lay a 3½-foot-long 4×4 beam across the tops of those pipes. Place a shorter 4×4 on top of the longer beam for the coupler to lower onto. Zero out the scale to ensure an accurate reading.

From there, lower the trailer coupler until it’s resting directly on the smaller 4×4, read what the scale says, and multiply whatever weight it shows by 3—because the scale and brick were set three feet apart; if they were 4 feet apart, you’d multiply by 4, and so on—to get your tongue weight.

Need something more visual to understand these instructions? Check out this video, which modifies the process a little by resting the tongue jack on the long 4×4 alone, rather than using the coupler on a stack of wood. There are also helpful diagrams in this blog post by Gregory Hildstrom.

Commercial Weigh Station

If you prefer to drive to a commercial weighing station, you will need to follow these instructions.

First, hitch your fully loaded trailer up to your truck. Drive all four wheels of the truck onto the scale, leaving the trailer hitched up but making sure none of the trailer tires are on the scale.

Next, unhitch the trailer, making sure there’s no weight on the hitch at all and ensuring the trailer jack is not on the scale. Weigh the truck again without the weight of the trailer.

Subtract the second weight from the first weight to determine your tongue weight.

How to Calculate Trailer Tongue Weight Ideal Range

Knowing your trailer tongue weight is great, but really, it’s only half of the information needed to keep you safe. The other thing you need to know is the ideal weight range you’re looking for.

To find this number, you first need to know your loaded trailer weight. This can be obtained at a commercial weighing station. If you know the weight of your cargo, you can also determine the total weight of your RV by adding the empty trailer weight to the total weight of everything you plan to carry in it.

Once you know the weight of your loaded trailer, you can learn your ideal tongue weight by using percentages. Many people ask, “The tongue weight of a trailer should be what percent of the total trailer weight?” The answer? Anywhere between 9 and 14 percent.

This means that if your loaded trailer weighs a total of 6,000 lbs, your ideal tongue weight would be between 540 and 780 pounds.

How to Determine Tongue Weight Adjustments

Let’s say you find your trailer tongue weight and it’s way more or less than it should be. How do you fix this? Luckily, the fix is incredibly simple. All you have to do is adjust your cargo.

If your trailer tongue weight is too low, move some cargo toward the front of the trailer to even things out. Trailer tongue weights that are too high can be fixed by doing just the opposite.

Determining these tongue weight adjustments is not an exact science. You’ll just have to move things until you find a nice balance. Fortunately, this usually only takes one or two tries.

Trailer Tongue Weight Tips

Looking for more tips for keeping your trailer tongue weight in check and keeping your family safe on the road? Here are some of our favorites:

  • Check your tongue weight often. Some people will check before every trip. Even if you don’t go that far, you will definitely want to check every time you add or remove cargo and when you rearrange things.
  • Invest in a special scale. While you can get the job done with a bathroom scale, having a tongue weight scale on hand makes measuring so much easier.
  • Know the rules of weight distribution hitches. If you’re planning on using a weight distribution hitch, know that it will need to handle more than just your tongue weight. It will also need to be hefty enough to handle any cargo placed behind the back axle in the bed of your truck. If you’re finding your tongue weight to determine which hitch to buy, this is very important information to have.