Buyer tools
Four tools, each answering a question that decides whether money changes hands: what the truck can legally carry, whether the axle weights work under the limits that changed in August 2026, what a tyre size swap does to the driveline, and what freight will really cost on a part. Everything runs in the browser, costs nothing, and shows its working rather than emitting a number from nowhere.
Free tool
Payload calculator
GVM minus tare is the whole answer, and almost nobody runs it before buying. Legal payload from the plate numbers, the 4.5 tonne car-licence boundary called out, and what a trailer does to payload through GCM.
Open the calculatorFree tool
Axle mass calculator
The general mass limits changed on 1 August 2026: tandem to 17 tonnes, tri-axle to 21. The current per-group limits with every figure linked to its NHVR source, and a checker for your own axle weights.
Open the calculatorFree tool
Tyre diameter calculator
11R22.5 to 295/80R22.5 changes the rolling diameter, the speedo, the work diary and where the engine sits at 100km/h. Compare any two truck sizes and see the shift before you buy the rubber.
Open the calculatorFree tool
Parts shipping calculator
Put in the size of the packed box and read the weight the carrier will actually bill you for. Exact Australia Post pricing between capitals, a straight answer when a part is too big to price online, and a quote block for the freight desk.
Open the calculatorLooking for a machine rather than a number
Tools answer one question at a time. To see what is actually for sale, browse every current listing by category, make and state, or put your own gear in front of buyers on the free listing form.