How to Weigh Your RV at a CAT Scale

More than half of all RVs that get weighed turn out to be overweight. Not by a little — many are hundreds of pounds over their rated limits. That’s a problem because overloaded rigs stop slower, handle worse, and blow tires more often. Insurance companies can deny your claim if the rig was over its GVWR at the time of an accident, and weigh stations can hit you with fines on the spot.

The good news is that checking your weight takes about ten minutes and costs less than a campground meal. CAT Scale operates over 2,200 truck scales across the U.S. and Canada, and every one of them works for RVs. This guide walks you through the entire process — from finding a scale to reading your results and knowing what to do next.

Why You Need to Weigh Your RV

The numbers are hard to ignore: 56% of RVs that get weighed are overweight. Among tow vehicles specifically, the number climbs to 60%. Tire blowouts triggered by overloading cause more than 70,000 accidents each year nationwide.

Beyond safety, there are financial consequences. If you’re involved in an accident and your RV was over its rated weight, your insurance provider can deny the claim entirely. Weigh station inspectors can issue citations and fines for exceeding your GVWR or GAWR. And chronic overloading accelerates wear on tires, brakes, and suspension components — problems that compound quietly until they become expensive.

Weighing isn’t a one-time task, either. You should weigh your rig after any significant modification (solar panels, lithium batteries, roof racks), after a major loading change (seasonal gear swap, extended boondocking supplies), and ideally at least once a season to catch weight creep before it catches you.

What Is a CAT Scale?

A CAT Scale is an industrial weighing platform found at truck stops across North America. Each scale has three separate platforms arranged in a line. You drive your rig across all three so that each axle group sits on its own platform, and the scale reads all of them simultaneously.

CAT Scales are located at most major truck stop chains — Pilot, Flying J, Love’s, and Travel Centers of America all have them. You can find the nearest one using the CAT Scale Locator app or at catscale.com.

One detail worth knowing: CAT Scale guarantees the accuracy of its weights. If you weigh in under your limits on a CAT Scale and then get an overweight fine at a weigh station, CAT Scale will reimburse the fine and send a representative to court as a witness. That’s a level of confidence you won’t find at a random gravel-pit scale.

What CAT Scales Measure — and What They Don’t

CAT Scales give you axle group weights and a total gross weight. That’s enough to check your rig against its GVWR, each GAWR (front and rear), and GCWR if you’re towing.

What they can’t do is weigh individual wheels or corners. If you need individual wheel position weights — for example, to check whether one side of your motorhome is significantly heavier than the other — you’ll need a service like RVSEF or Escapees SmartWeigh (more on those later).

What You Need Before You Go

Download the Weigh My Truck app. It’s free on iOS and Android. Set up your account and add a payment method before you get to the scale — you don’t want to fumble with registration while parked on a platform with truckers waiting behind you.

Load your rig the way you actually travel. Fill the fuel tank. If you normally travel with water in your fresh tank, fill that too. Load your gear, your passengers, and your pets. The whole point is to weigh the rig in its real-world travel configuration.

Know your ratings. Before you go, write down your rig’s GVWR, GAWR (front and rear), and GCWR (if towing). These numbers are on the federal certification label — usually on the driver’s-side door frame or the front-left of the trailer. You can also plug them into the Arvee GVWR calculator to check everything in one place.

Step-by-Step: How to Weigh at a CAT Scale

1. Find a Scale

Open the CAT Scale Locator app or visit catscale.com/cat-scale-locator. Search by your location or along your route. Most major truck stops have one.

2. Drive Onto the Scale

Yellow lines painted on the ground mark the boundaries of each platform. Position your rig so that each axle group sits on its own platform. (See the positioning guide below for your specific RV type.) Pull forward slowly and stop when your axles are centered on the platforms.

3. Open the App

Launch the Weigh My Truck app. It uses GPS to detect your location and identify the scale. Confirm the location, or enter the four-digit code displayed on the sign at the scale.

4. Get Your Results

The app processes the weigh and displays your axle weights within seconds. You’ll see the weight on each platform and a total gross weight. A PDF scale ticket is emailed to you automatically.

5. Drive Off

Pull forward off the scale. That’s it for your first weighing.

6. Reweigh If Needed

If you’re towing and want to calculate tongue weight or pin weight, you’ll need a second weighing with just the truck (see the tongue weight section below). Pull off, park the trailer safely in the lot, and drive back onto the scale. Reweighs within 24 hours at the same location cost only $4.00.

Positioning Your Rig on the Scale

How you position your rig depends on what you’re driving. Here’s the setup for each common configuration:

Motorhome (no tow vehicle):

Platform 1: Front (steer) axle
Platform 2: Rear (drive) axle
Platform 3: Empty

Motorhome with tow car (toad):

Platform 1: Motorhome front axle
Platform 2: Motorhome rear axle
Platform 3: Tow car

Truck + travel trailer:

Platform 1: Truck front (steer) axle
Platform 2: Truck rear (drive) axle
Platform 3: Trailer axle(s)

Truck + fifth wheel or gooseneck:

Platform 1: Truck front (steer) axle
Platform 2: Truck rear (drive) axle
Platform 3: Trailer axle(s)

For tow setups, you’ll need two separate weighings — one coupled and one with just the truck — to calculate tongue weight or pin weight. More on that next.

How to Calculate Tongue Weight (or Pin Weight)

A CAT Scale doesn’t display tongue weight directly, but you can calculate it with two weighings:

Weighing 1 — Coupled: Weigh your full rig (truck + trailer) as described above. Record the truck rear axle weight from Platform 2.
Weighing 2 — Truck only: Disconnect the trailer in the parking lot and weigh just the truck. Record the rear axle weight again.
Subtract: The difference between the coupled rear axle weight and the truck-only rear axle weight is your tongue weight (travel trailer) or pin weight (fifth wheel).

For travel trailers, tongue weight should be 10-15% of the total loaded trailer weight. For fifth wheels, pin weight should be 15-25%. If your numbers are outside that range, you likely have a loading or weight distribution issue.

What to Do with Your Numbers

Once you have your weights, compare each number against the corresponding rating:

Total gross weight vs. your GVWR — Is the fully loaded vehicle under its maximum?
Front axle weight vs. front GAWR — Is the front axle within limits?
Rear axle weight vs. rear GAWR — Is the rear axle within limits?
Combined weight (truck + trailer) vs. GCWR — Is the total tow setup within limits?

If any number exceeds its rating, you’re overweight on that metric and need to reduce load, redistribute cargo, or both. Common fixes include traveling with less water, removing heavy items you don’t need on every trip, and redistributing cargo from an overloaded axle to one with more margin.

The fastest way to check all of these at once is to plug your numbers into the Arvee GVWR calculator. It checks GVWR, GAWR, GCWR, payload, and tongue weight in a single pass and tells you exactly where you stand.

When a CAT Scale Isn’t Enough

CAT Scales are great for axle-level data, but they have one blind spot: they can’t tell you how weight is distributed side to side. You can be within your GAWR overall and still have one side significantly heavier than the other — overloading individual tires without knowing it.

For that level of detail, you need wheel position weighing:

RVSEF (RV Safety & Education Foundation) attends RV rallies and events nationwide with portable calibrated scales. They weigh each individual tire position, provide a detailed report, and offer one-on-one consultation about your results. Cost is $70 per RV. They recommend wheel position weighing every 3-4 years or after chassis modifications.

Escapees SmartWeigh offers the same individual-wheel weighing at fixed locations in Livingston, TX; Bushnell, FL; and Congress, AZ. The service includes a weighmaster consultation to help you redistribute load if needed.

For most RVers, a CAT Scale weigh once or twice a year covers the basics. Add a wheel position weigh every few years — or after any major modification — for the full picture.

Quick Reference: CAT Scale Costs

Service	Cost
First weigh	$13.50
Reweigh (same location, within 24 hours)	$4.00
Maximum cost per 24-hour period	$25.50

Get Your Numbers, Then Check Them

Weighing your RV is one of the simplest things you can do for safety — and one of the most commonly skipped. Ten minutes at a truck stop gives you the data you need to know whether your rig is safe to drive or quietly overloaded.

Once you have your axle weights, plug them into the free Arvee GVWR calculator to check every rating at once. And if you want to understand the weight ratings themselves, start with GVWR vs GAWR vs GCWR Explained or learn about the most common RV weight mistakes so you can avoid them before your next trip.