Axle Weight Calculator for Trucks and Trailers

Use this free axle weight calculator to check a rigid truck, a tractor unit or a truck-and-trailer combination before it leaves the yard. Enter your axle layout and unladen weights, place each load where it sits on the deck, and read the weight on every axle, the kingpin or drawbar load, and how much more you can legally carry. It checks against New Zealand’s as-of-right limits (Land Transport Rule: Vehicle Dimensions and Mass 2016); outside New Zealand, switch to custom limits and enter the axle and gross limits that apply to you, in kg or lb.

Loadsense Weighing Systems

Axle Weight Calculator

Check a truck, tractor unit or truck-and-trailer combination against New Zealand as-of-right axle and gross mass limits before it leaves the yard. Enter the axle layout and unladen weights, drop each load where it sits, and read the weight on every axle.

Side view of the configured vehicle with axle weights Drag a load to move it

Vehicle

Truck positions measure from the front axle group centre

Start from a common layout

Truck axles

mm
mm
Centre to centre, adjacent axles

Truck dimensions

mm
Front group centre to rear group centre
mm
Bumper to first axle
mm
Last axle to rear of chassis or body
mm
Behind front group centre
mm
Drawing only

Truck unladen weights (weighbridge or onboard scale)

kg
kg
kg
Weighed without the trailer. Include body, fuel and driver if they were on board

Trailer

Manufacturer ratings (optional)

kg
kg
kg
kg
kg
kg
From the certificate of loading or the chassis plate. The lower of the legal limit and the rating applies.

Loads

On the truck

Position is the load's centre of gravity. Truck loads measure behind the front axle group centre; trailer loads measure behind the kingpin (semi), the trailer's front axle group (full) or its axle group (simple). Negative values sit ahead.

Axle weights

Per axle

Compliance checks

    Stop estimating. Weigh every axle as you load.
    Loadsense onboard truck and trailer scales show live axle group weights in the cab and on your phone, so the numbers above become measurements.
    See truck and trailer scales

    How it works. Each load's weight is shared between the axle groups that support it by lever arm: the closer a load sits to a group, the more of it that group carries. A semi-trailer puts its kingpin share onto the tractor through the fifth wheel; a simple (centre-axle) trailer puts its drawbar share onto the tow hitch, which unloads the truck's front axle; a full trailer carries itself. Weight within a group is assumed to share equally between its axles (a load-sharing suspension).

    Limits. New Zealand figures are the general-access (as-of-right) limits in Schedule 3 of Land Transport Rule: Vehicle Dimensions and Mass 2016: Table 1.1B for individual axles, Tables 1.2 to 1.5 for axle sets, Table 2.1 for the total mass across any span of axles (up to 44,000 kg) and Table 2.2 for combinations with seven or more axles (45,000 and 46,000 kg). Tyre classes follow the Rule's section-width definitions. HPMV and overweight permits, passenger service vehicles, B-trains and multi-trailer combinations are not covered.

    Indicative only. Results depend on the figures you enter and on static, evenly distributed loading. Road-legal weight is what the axle actually carries, so confirm with a certified weighbridge or a Loadsense onboard scale, and never exceed the manufacturer's ratings, towing connection ratings or the certificate of loading.

    Axle weights: quick answers

    How is the weight on each axle worked out?

    Each load is shared between the axle groups that support it by lever arm: the closer the load sits to a group, the more of it that group carries. A semi-trailer passes its kingpin share onto the tractor through the fifth wheel. A simple (centre-axle) trailer passes its drawbar share onto the tow hitch, which loads the truck’s rear axles and unloads the front. Weight within a group is assumed to share equally between its axles.

    Can I be overloaded on one axle when the gross is legal?

    Yes. Axle and axle-set limits apply separately from the gross limit, so a load placed too far forward or back can overload one group while the total is well under the maximum. Moving the load along the deck often fixes it without unloading, and the calculator shows how much more can go on, or must come off, at the payload position.

    What are the New Zealand limits it uses?

    Schedule 3 of the VDAM Rule 2016 (general access, no permit): a single standard-tyred steer axle up to 6,000 kg, a twin-tyred axle up to 8,200 kg, a twin-tyred tandem set 14,500 to 15,500 kg depending on spacing, a tri-axle set 16,000 to 18,000 kg, a quad-axle set 20,000 kg, and a total across any span of axles set by the distance between the first and last axle, up to 44,000 kg (45,000 and 46,000 kg for seven- and eight-axle combinations at the required spacing).

    How accurate is this?

    It is indicative. Results depend on the figures you enter and assume static, evenly distributed loading. The road-legal weight is what each axle actually carries, so confirm it with a certified weighbridge or a Loadsense onboard scale, and never exceed the manufacturer’s ratings or the certificate of loading.