Steer, drives, trailer in. Holes and notches out.
Type the three weights from your scale ticket. AxleSet tells you exactly how many holes to slide the tandems and how many fifth-wheel notches to move — for your trailer, in your state, with no signal needed.
| STEER | 11,500 |
| DRIVES | 35,000 |
| TRAILER | 32,000 |
| GROSS | 78,500 |
Worked by the app for a typical 53-ft van (6-inch holes, tandems at 40 ft). Your trailer gives its own number.
Not a rule of thumb
"About 400 pounds a hole" is a guess. The real number depends on your trailer: the weight the tandems carry, the hole spacing on the rail, and the kingpin-to-tandem distance. AxleSet takes your rig's measurements once and works every hole and every fifth-wheel notch from the geometry — then shows you what happens at each one, so you can see why the answer is what it is.
The checks the other calculators skip
- Federal Bridge Formula (23 CFR 658.17) on every group of consecutive axles, including the 36-foot two-tandem exception. Verified cell by cell against the published table.
- Kingpin-to-rear-axle rules — California's 40 feet and the other states that have one, including the ones that measure differently.
- All 50 states: single, tandem, gross, bridge, and the fine schedule, each read on the state's own statute or DOT page and cited. If a state could not be confirmed from an official source, the app says not verified and falls back to federal — it never guesses.
- Interstate vs. state highway where the limits differ, and the APU allowance.
Built for the scale house
- Scan the CAT Scale ticket with the camera; the numbers are read on the phone.
- Save tickets with the photo, reweigh and compare, export a PDF.
- Several rigs saved — switch trailers in one tap.
- Calibrate the kingpin-to-tandem distance from two weighings, no tape measure.
- CAT Scale locations near you, with directions.
- Dark mode for the night shift. Big numbers, big buttons.
AxleSet is a reference and a calculator, not legal advice. Laws change, permits change things, and the officer's table wins at the roadside. CAT Scale is a trademark of its owner; AxleSet is not affiliated with CAT Scale Company. Scale locations © OpenStreetMap contributors (ODbL).