Heat-capacity matching, work capacity factors, pressure adjustments, cost-per-tonne. The math you actually need.
Tonne Kilometre Per Hour for haul truck tyre heat-capacity matching. Enter cycle data, get required TKPH with temperature correction.
These calculators are provided as a general technical reference. Results are illustrative and based on the formulas published in the calculator. They are not a substitute for: (a) current manufacturer specifications for a specific tyre, (b) engineering review of a specific machine and application, (c) qualified inspection by a competent tyre engineer or fitter, or (d) compliance with AS4457:2019 and OEM operating limits. The user is responsible for confirming results against current manufacturer data and the actual operating envelope before acting on the output. Always include manufacturer safety margins.
Ton Miles Per Hour, imperial equivalent of TKPH for North American manufacturer specifications.
Work Capacity Factor for wheel loaders and dozers. Different math from TKPH, similar purpose: match tyre to duty.
Cold-fill pressure adjustments for altitude, ambient temperature, and load variation.
Lifecycle cost per operating hour for a tyre, purchase, fitment, expected service life, scrap value.
Tyre cost per tonne hauled, with cycle data and expected tyre life. Useful for tier-one vs mid-tier brand comparison.
Cross-reference tyre size to compatible rim widths, including load capacity and valve placement.
It works out the TKPH (Tonne Kilometre Per Hour) figure a haul truck tyre has to cope with on the cycle you enter, which is mean tyre load multiplied by average haul speed, then corrected for ambient temperature. You enter loaded weight, empty weight, number of tyres on the machine, round-trip distance, cycle time and ambient temperature. The output is indicative reference for comparing against a manufacturer's published TKPH rating.
Mean tyre load is the average of loaded and empty machine weight, divided by the number of tyres on the machine. That is a whole-machine average, not a per-axle figure. In our view it is a fair first pass, but real haul trucks carry more weight on the drive axle than the steer axle, so it is worth confirming actual axle loads with the OEM data before selecting on the result.
TKPH is a heat rating, and hot air cools a working tyre less. This calculator adds 5% to the requirement for every 5°C of ambient above 38°C, so a Pilbara summer shift lands on a higher number than the same cycle in cool weather. Manufacturers publish their own ambient correction guidance, and theirs governs over ours.
The calculator shows a figure 15% above the calculated requirement, purely as an illustration of what a margin looks like. In our view carrying some margin is sensible because planned cycle data rarely matches the worst shift, but the size of it is not our call: use the manufacturer's rated TKPH for the specific tyre and the safety margin they state for it.
No. The results are indicative general reference based on the formula shown on the page. They are not a substitute for current manufacturer specifications for a specific tyre, engineering review of a specific machine and application, qualified inspection by a competent tyre engineer or fitter, or compliance with AS4457:2019 and OEM operating limits. Confirm the output against current manufacturer data and your actual operating envelope before acting on it.