Trailer Clearance Calculator

Plan and validate Western Australian road-legal vehicle combinations for clearance compliance.

This calculator enables rapid visualisation and geometric analysis of trucks, trailers, dollies, and other heavy vehicles through all required articulation angles.

Simply select a standard legal combination or customise vehicle dimensions, then run a clearance check to see potential collision points and ensure your configuration meets Main Roads WA requirements.

Interactive SVG previews and summary reports make it easy to identify compliance issues and support rule-aligned vehicle planning.

Select Vehicle

Configure Vehicle Units

Prime Mover side view

H2: Cab Ground Height (m)

H1: Body Ground Height (m)

Body Height (m)

CFW: Cabin to Fifth Wheel (m)

FOH: Forward Overhang (m)

Body Length (m)

Rear Fifth Wheel Clearance (m)

Body Width (m)

Width must be 2.0–2.65 m.

FWH: Fifth Wheel Height (m)

Kingpin Ground Height (m)

DB: Drawbar Length (m)

Drawbar Height (m)

Pin Coupling Attachment Height (m)

Coupling Underrun (m)

Semi Trailer side view