Axle Load Calculator

This is a calculator, designed to calculate the relative loads at both the kingpin (fifth wheel) and bogie (rear axle combination) of a trailer. It is capable of handling any length of trailer of either straight or step-frame design, together with 3 independent loads and a secondary deck.

The image drawing can be saved by simply right-clicking and selecting "Save as".

All loads are assumed to be evenly distributed.

Default figures have been provided, but you can use the samples below for convenience.

The following buttons will auto-fill common dimensions in the form fields below.

You will still be able to customise the values in each field to suit.

Body Types

13.7m Tri-Axle Curtainsided Trailer

9m Single Axle Urban Curtainsided Trailer

13.6m Tandem Axle Box Van Trailer

13.7m Curtainsided Fixed Double Deck

13.6m Box Van Step-Frame Lifting Deck

13.6m Box Van Straight Frame Lifting Deck

13.7m Curtainsider Lifting Deck

15.650m Curtainsided Longer Semi-Trailer (LST)

DistanceThis is typically 1.6m for full length trailer but tends to get shorter for urban trailers. from kingpin to front of trailer	m
Trailer LengthTypically 13.7m for a curtainsider and 13.6m for box vans	m

Operating GVWGross Vehicle Weight	kgs
Tractor Weight	kgs
Trailer Tare WeightUnladen trailer weight.	kgs
Max Load on Kingpin	kgs

Axle Number
Axles Weight (each)	kgs
Axle Capacity (each)	kgs
Kingpin to centrelineTypically 6.79m for tri, 7.445m for tandem or 8.1m for single axle. of front axle	m
Front axle spread (If tandem or tri)	m
Rear axle spread (If tri)	m

DistanceTypically 4.270m for step-frame trailers. from front of trailer to start of load	m
Load Length	m
Load Weight	kgs

Distance from front of trailer to start of load	m
Load Length	m
Load Weight	kgs

Distance from front of trailer to start of deck	m
Deck Length	m
Deck Weight	kgs

2nd Deck Load

Distance from front of trailer to start of load	m
Load Length	m
Load Weight	kgs

This calculator was designed to offer general guidance when calculating axle loads. All generated drawings are subject to final engineering confirmation and Don-Bur accepts no liability for actions or decisions based on information from this calculator alone.