RV Tongue Weight Guide
If you’ve ever felt your travel trailer start to sway on the highway — that unsettling side-to-side fishtail that tightens your grip on the steering wheel — there’s a good chance tongue weight was the culprit. Too little and the trailer wags the truck. Too much and the truck’s rear sags, the front tires lose grip, and braking gets sketchy.
Tongue weight is one of the most important numbers in your towing setup, and it’s also one of the easiest to get wrong. This guide covers what tongue weight is, the target range you should aim for, three practical ways to measure it, and what to do when the numbers come back wrong.
What Is Tongue Weight?
Tongue weight is the downward force that your trailer’s coupler exerts on the tow vehicle’s hitch ball. Think of it as the portion of the trailer’s total weight that rests on the truck instead of on the trailer’s own axles.
Every conventional (bumper-pull) trailer transfers some of its weight forward through the tongue to the hitch. The amount depends on how the trailer is loaded — specifically, how much weight is in front of the trailer’s axle versus behind it.
For fifth wheels, the equivalent is called pin weight — the downward force at the kingpin where the trailer sits on the truck-bed hitch.
The 10-15% Rule
The target tongue weight for a conventional travel trailer is 10-15% of the total loaded trailer weight. For fifth wheels, pin weight should be 15-25% of the loaded trailer weight.
Below 10%, you’re in the danger zone for trailer sway. Above 15%, you risk overloading the tow vehicle’s rear axle and losing front-end steering response.
Quick Math
| Loaded Trailer Weight | Target Tongue Weight (10-15%) |
|---|---|
| 4,000 lb | 400 - 600 lb |
| 6,000 lb | 600 - 900 lb |
| 8,000 lb | 800 - 1,200 lb |
| 10,000 lb | 1,000 - 1,500 lb |
What Happens When Tongue Weight Is Wrong
Too Little Tongue Weight
When tongue weight is below 10%, the trailer’s center of gravity sits too far behind its axle. At highway speeds, any disturbance — a gust of wind, a lane change, a passing truck — can start the trailer swaying. Once sway starts, it tends to amplify rather than dampen, and at a certain point the trailer controls the truck instead of the other way around.
Physically, low tongue weight lifts the tow vehicle’s rear, reducing rear-tire traction and making the truck easier to push around.
Too Much Tongue Weight
Excess tongue weight pushes the tow vehicle’s rear down and lifts the front. The effects are subtler than sway but just as dangerous:
- Reduced steering response — lighter front tires have less grip
- Longer braking distances — weight shifts away from the front brakes
- Headlights aim too high — reducing your nighttime visibility and blinding oncoming traffic
- Rear axle stress — can exceed the tow vehicle’s rear GAWR even if total weight looks fine
Three Ways to Measure Tongue Weight
Method 1: Tongue Weight Scale
A dedicated tongue weight scale is the simplest option for at-home measurement. The Sherline LM series and Fastway SIMPLE WEIGH are popular choices, ranging from $80 to $200 depending on capacity.
How to do it:
- Park your loaded trailer on a level surface and chock the wheels
- Place the tongue weight scale on the ground where the tongue jack normally sits
- Lower the tongue jack onto the scale until the coupler lifts clear of the hitch ball
- Read the scale — that’s your tongue weight
This method is accurate and repeatable, making it ideal for dialing in your load distribution. The limitation is that most tongue weight scales max out around 2,000 lb, which covers most travel trailers but not large fifth wheels.
Method 2: Bathroom Scale with Lever
If you don’t want to buy a dedicated scale, you can improvise with a bathroom scale, a sturdy board (a 4-foot 2x4 works), and a brick or block.
How to do it:
- Place the block on the ground about 1 foot from where the tongue will rest
- Rest one end of the 2x4 on the block (this is your fulcrum)
- Place the bathroom scale under the far end of the 2x4 (about 3 feet from the block)
- Lower the tongue jack onto the 2x4 at the near end (right above the block side)
- Read the bathroom scale and multiply by your lever ratio
The lever ratio depends on your distances. If the scale is 3 feet from the fulcrum and the tongue is 1 foot from the fulcrum, the ratio is 3:1 — so a 200 lb scale reading means 600 lb of actual tongue weight. Measure your distances carefully, because the accuracy of this method depends entirely on the ratios.
Method 3: CAT Scale (Best for Real-World Numbers)
This is the most practical method for measuring tongue weight as you actually travel, because it uses your real loaded rig on a certified scale.
How to do it:
- Weigh your truck with the trailer coupled — note the truck’s rear axle weight from Platform 2
- Pull off, disconnect the trailer in the parking lot, drive back on
- Weigh the truck alone — note the rear axle weight again
- Subtract: Coupled rear axle weight minus truck-only rear axle weight = tongue weight
A first weigh costs $13.50, a reweigh is $4.00, so the total cost for both weighings is $17.50. For a complete walkthrough of the CAT Scale process, see our guide to weighing your RV at a CAT Scale.
How to Fix Tongue Weight Problems
Tongue Weight Too High
Move heavy items toward the rear of the trailer — behind the axle centerline. Common culprits for front-heavy loading include batteries mounted on the tongue, heavy toolboxes in the front storage compartment, and full propane tanks.
Tongue Weight Too Low
Move heavy items forward — toward the tongue side of the axle. The general rule is to keep about 60% of your cargo weight forward of the trailer’s axle centerline. If you consistently struggle with low tongue weight, your trailer may have a design-related balance issue that a weight distribution hitch can help compensate for.
When to Use a Weight Distribution Hitch
A weight distribution hitch (WDH) uses spring bars to redistribute tongue weight across all axles — both the tow vehicle’s and the trailer’s. It doesn’t change your tongue weight, but it does spread the load so no single axle bears the brunt.
A WDH is recommended for any towing setup over 5,000 lb. Most half-ton trucks require one when towing travel trailers. If your truck’s rear sags noticeably when you hitch up, or if the front end feels light, a WDH is likely the right fix.
Check Your Tongue Weight with the Calculator
Once you have your tongue weight measurement, plug it into the Arvee GVWR calculator along with your other weights. The calculator checks tongue weight against your tow vehicle’s hitch rating and verifies that the added load doesn’t push your rear axle over its GAWR.
For a broader look at all the weight ratings involved in towing, see GVWR vs GAWR vs GCWR Explained. And if you suspect your rig is carrying more than it should, our guide to common RV weight mistakes covers the errors that catch most RVers off guard.