The Preferred Heavy Equipment Trailer Dealer

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Axle Weight Distribution Calculator

Enter your rig + load and get real-time per-axle weights, GVW, and federal compliance alerts. Start with a preset or plug in your own tractor and trailer numbers.

Tandem-axle tractor + tri-axle lowboy, ~26 ft well

Load

Tractor

Trailer

Gross Vehicle WeightPERMIT
138,000 lb
Federal non-permit limit: 80,000 lb
Steer axle18,472 lb
100% of 12,000 lb limit
Drive axles (tandem)59,987 lb
100% of 34,000 lb limit
Trailer axles (3-axle)59,542 lb
100% of 42,000 lb limit

Breakdown

Payload on kingpin → tractor
38,958 lb
Payload on trailer axles
46,042 lb
Total on kingpin (inc. trailer tare)
47,458 lb
Total tare
53,000 lb
Payload
85,000 lb
⚠ Steer axle: 18,472 lb exceeds 12,000 lb federal limit by 6,472 lb (permit required).
⚠ Tandem drive axles: 59,987 lb exceeds 34,000 lb federal limit by 25,987 lb (permit required).
⚠ Tridem trailer axles: 59,542 lb exceeds 42,000 lb federal limit by 17,542 lb (permit required).
⚠ Gross vehicle weight: 138,000 lb exceeds 80,000 lb federal limit by 58,000 lb (permit required).

How this calculator works

This is a classic single-kingpin rig weight-distribution model. Your payload sits on the trailer deck. The fraction that ends up on the kingpin(and through it, the tractor's 5th wheel) is determined by how far forward the center of gravity is from the trailer axle group — the closer to the kingpin, the more weight transfers to the tractor.

On the tractor, the kingpin load splits between the steer axle and the drive axle group based on how far ahead of the drive group your 5th wheel is positioned. A slid-back 5th wheel puts more weight on drives; a slid-forward 5th wheel unloads the drives onto the steer.

Federal limits we check against

  • Steer axle: 12,000 lb
  • Single axle: 20,000 lb
  • Tandem axle: 34,000 lb
  • Tridem axle: 42,000 lb (varies by state)
  • GVW: 80,000 lb (non-permit)

State rules vary — Georgia allows some higher non-permit weights on specific axle configurations, and many states issue routine oversize/overweight permits well beyond these numbers. Use this tool for planning; verify with your DOT before dispatch.

Need a trailer spec'd for your exact load?

Talk to TM— we'll match kingpin-to-axle, deck length, and axle count to your payload profile so you're legal on every haul, not just on the scale.