How do I read a CAT scale ticket?

STEER, DRIVE and TRAILER explained, the two-pass weigh that separates truck from tongue weight, and the arithmetic that turns a $15 ticket into real numbers.

Updated September 19, 2026

What the three lines mean

A CAT scale ticket has three weights on it, named for the truck the scale was designed for rather than for yours. STEER is whatever sat on the first platform — for a pickup, the front axle. DRIVE is the second platform, your rear axle. TRAILER is the third platform, your trailer’s axles. There is also a GROSS figure, which is simply the three added together. The scale weighs each platform independently and prints what each one carried; everything useful comes from that separation.

What the ticket does not print is tongue weight, and that is the number most people drove there for. Tongue weight is not something a scale can see directly, because the tongue is not resting on the scale — it is resting on the truck, which is resting on the scale. You get it by subtraction, which takes two weighs.

The two-pass weigh

Pass one: pull on hitched, with the trailer’s axles on their own platform and the weight-distribution bars disconnected. Press the intercom, give them your truck number or say it is a first weigh, and pull forward. Pass two: drop the trailer in the lot, drive the truck back onto the scale alone, and ask for a reweigh on the same ticket number — that is the few-dollar one rather than another full price. You now have the truck’s axles carrying a trailer, and the truck’s axles carrying nothing.

Three numbers fall out of those two tickets. Tongue weight is the truck’s gross in pass one minus the truck’s gross in pass two: whatever the truck gained when the trailer was attached came down the tongue. Loaded trailer weight is the TRAILER platform figure plus that tongue weight, because the part of the trailer sitting on the ball was weighed as part of the truck. And the rear axle load — the one that quietly exceeds its rating — is the DRIVE figure from pass one, straight off the ticket with no arithmetic at all.

Worked example

The truck weighed 6,830 lb hitched and 5,910 lb alone, so 920 lb came down the tongue. The trailer’s own axles carried 6,560 lb, which makes the loaded trailer 6,560 + 920 = 7,480 lb. Tongue weight as a percentage is 920 ÷ 7,480 = 12.3%, comfortably inside the 10–15% a bumper-pull wants — see how much tongue weight is right for what the ends of that range feel like.

Two things in that table are worth more than the tongue weight. The truck alone at 5,910 lb is the real curb weight of your truck with its toolbox, bed liner, full tank and the junk behind the seat — not the brochure’s figure for a stripped one, and the honest number to subtract from GVWR when computing payload capacity. And the front axle dropping is the tell that a weight-distribution hitch would earn its keep: a bumper-pull tongue sits behind the rear axle, so it levers weight off the front.

Checking it against the ratings

A ticket is only useful next to the stickers. Take four comparisons, in this order. The pass-one truck total against GVWR — that is the truck fully loaded including tongue weight. The DRIVE figure against the rear GAWR, which is the limit a heavy tongue breaks first and the one no brochure mentions. The computed loaded trailer weight against the trailer’s own GVWR. And the tongue percentage against 10–15% for a bumper-pull, 15–25% for a fifth wheel’s pin. If any of the four is over, the ticket has told you which one and by how much, which is a far better position than the guesswork in is my truck overloaded.

Getting a reading worth trusting

Weigh the rig the way you actually travel: water tanks at the level you tow with, propane full, bikes on the rack, everybody in their seats. An empty-tank weigh is a number for a trailer you are not towing — fresh water alone runs 8.34 lb per gallon, so a 40-gallon tank is 334 lb that appears and disappears depending on when you weighed. Keep the ticket; it is the only place your true curb weight is written down, and re-weighing after a big change in how you pack costs a few dollars rather than another full weigh.