Axle Balance Axle weight calculator

Free axle weight calculator for tractor-trailers

For 5-axle eighteen-wheelers: steer, drives and trailer tandems

In short: enter the three weights from your scale ticket (steer, drives, trailer tandems) and which hole you're on. Axle Balance tells you which way to slide your trailer tandems, how many holes, and what your new axle weights should be. It's free and runs offline in the cab.

What you enter

Steer, drive and trailer tandem weights from your CAT scale or any certified scale ticket.
The hole your tandems are on now. The app counts holes from the front of the slider rail.
The state you're in or headed to, so you don't slide past that state's kingpin-to-rear-axle limit.

What you get back

A slide direction and hole count, for example "Back truck up 4 holes," with an arrow on the truck showing which way to go.
Your new estimated weights on every axle group, checked against the federal 12,000 / 34,000 / 34,000 / 80,000 lb setup most drivers aim for.
A per-hole estimate that gets more accurate every time you log a scale ticket. Axle Balance learns how many pounds move per hole on your truck and trailer.

Federal limits the calculator checks

On the Interstate System, federal law limits a single axle to 20,000 lb, a tandem axle group to 34,000 lb, and gross vehicle weight to 80,000 lb, unless the bridge formula sets a lower number (FHWA). Most states use the same limits on their other main highways, but a few have grandfathered higher weights or stricter local rules. For how axle spacing affects legal weight, see the bridge formula guide.

Why drivers balance at the scale

A load can be legal at 80,000 lb gross and still be overweight on one axle group. The usual fix is to slide the trailer tandems, which shifts weight between the drives and the trailer axles, or to slide the fifth wheel, which shifts weight between the steer and the drives. The tandem slide guide walks through both.

Free and Pro

The quick balance calculator is free. Pro adds a load planner that places pallets by the foot, bridge formula and kingpin checks, a slide advisor, state hole rules along a route, a Load info board for BOL and appointment details, and a Fleet manager that syncs with drivers.

Know which way to slide before you get back on the scale. Axle Balance is a free calculator made by a trucker. Enter your scale ticket and it tells you which way to slide your tandems and how many holes, plus your fifth wheel. Works offline in the cab.

Open the free calculator

Estimates and general information only, not legal advice. Laws change and enforcement varies. Always confirm on a certified scale and with the state before you rely on it. See the Terms of Use.