How to Weigh Your Truck + Trailer at a CAT Scale (Step-by-Step)
If you want to know whether your towing setup is actually safe, a real weigh-in beats any spreadsheet,
brochure, or guess.
The good news: weighing a tow vehicle and trailer is simple if you do it in the right order.
This guide walks you through exactly what to weigh and how to interpret the numbers.
Why this matters:
Most “it tows fine” setups are overloaded on payload or rear axle long before they hit tow rating.
A scale makes the truth obvious.
What You Need Before You Go
Your vehicle’s door sticker payload and GVWR
Rear axle rating (RAWR) / GAWR (on sticker or manual)
Trailer GVWR (on trailer sticker)
Your rig loaded like a real trip (passengers, gear, full hitch hardware)
Ideally, load your trailer the way you actually travel: propane, batteries, water (if you carry it),
and your normal cargo.
Quick Definitions (So the Ticket Makes Sense)
GVWR: max weight of the tow vehicle itself
GAWR / RAWR: max weight on each axle (rear axle is the usual failure point)
GCWR: max combined weight of vehicle + trailer (if you have it)
Payload: how much weight you can add to the vehicle (people + cargo + hitch + tongue/pin)
The Best Weighing Method: 3 Passes
Three passes gives you the cleanest answers:
(1) vehicle alone, (2) hitched without weight distribution engaged, (3) hitched with weight distribution engaged (if you use it).
Important:
A weight distribution hitch can move weight between axles, but it does not make payload disappear.
Hitch hardware weight still counts.
Pass #1 — Tow Vehicle Only (Baseline)
Drive onto the scale with just the tow vehicle (no trailer).
If possible, load the vehicle with the same people and cargo you’ll have when towing.
Record front axle weight
Record rear axle weight
Record total vehicle weight
This is your baseline and makes the rest of the math simple.
Pass #2 — Hitched, WDH Not Engaged (If You Have One)
Hook up the trailer exactly how you tow it, but if you use a weight distribution hitch (WDH),
do this pass with the bars/chains not tensioned (or “not engaged”).
Front axle weight (vehicle)
Rear axle weight (vehicle)
Trailer axle weight(s)
Total combined weight
This pass is the easiest way to see how much the hitch load shifts weight to the rear axle.
Pass #3 — Hitched, WDH Engaged (If You Use It)
Now engage your WDH as you normally would and weigh again.
You’ll see weight move off the rear axle and back toward the front axle and trailer axles.
This pass answers: “Is my WDH adjustment helping axle balance?”
(It still doesn’t change your payload limit, but it can improve handling and stability.)
How to Read the Results
Here are the key checks most people care about:
Vehicle GVWR check: your hitched vehicle total (front + rear) should be ≤ GVWR
Rear axle check: rear axle should be ≤ RAWR/GAWR (this is the common one to fail)
Trailer check: trailer axle total should be ≤ trailer GVWR (and tire ratings)
Combined check: combined total should be ≤ GCWR (if you have it)
Payload shortcut:
Payload used ≈ (hitched vehicle total) − (vehicle-only total).
That “difference” includes tongue/pin weight + hitch hardware + anything you added for the trip.
What About Tongue Weight?
A simple estimate you can use:
Travel trailers: ~12–15% of loaded trailer weight on the hitch
Car trailers: ~10–15% (varies by load position)
5th wheels/goosenecks: often ~15–25% pin weight
The scale is the reality check. If your rear axle or payload margin is tight, tongue/pin weight is usually why.
If You’re Over: The Most Effective Fixes
Reduce tongue weight by moving cargo rearward in the trailer (carefully—maintain stability)
Remove cargo from the tow vehicle (payload is precious)
Carry less water/gear when possible
Upgrade tow vehicle (more payload is the real game-changer)
Want a quick estimate before you weigh?
Use the calculator to estimate tongue/pin weight and payload usage — then verify at a scale.