/ Calculators · Technical Tools

Free OTR tyre calculators.

Heat-capacity matching, work capacity factors, pressure adjustments, cost-per-tonne. The math you actually need.

/ 01 · Functional

TKPH Calculator

Tonne Kilometre Per Hour for haul truck tyre heat-capacity matching. Enter cycle data, get required TKPH with temperature correction.

/ Required TKPH
Enter haul cycle data above to calculate.
/ TALK TO JEWELL TYRES For tyre selection against a calculated TKPH, including manufacturer-rated comparisons and supply availability, submit a buy enquiry or call David direct on 0419 358 439.
/ 02 · COMING SOON

TMPH Calculator

Ton Miles Per Hour – imperial equivalent of TKPH for North American manufacturer specifications.

/ 03 · COMING SOON

WCF Calculator

Work Capacity Factor for wheel loaders and dozers. Different math from TKPH, similar purpose: match tyre to duty.

/ 04 · COMING SOON

Pressure Adjustment

Cold-fill pressure adjustments for altitude, ambient temperature, and load variation.

/ 05 · COMING SOON

Cost-per-hour

Lifecycle cost per operating hour for a tyre – purchase, fitment, expected service life, scrap value.

/ 06 · COMING SOON

Cost-per-tonne

Tyre cost per tonne hauled, with cycle data and expected tyre life. Useful for tier-one vs mid-tier brand comparison.

/ 07 · COMING SOON

Rim Compatibility

Cross-reference tyre size to compatible rim widths, including load capacity and valve placement.

/ Calculator disclaimer

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.