Calculators
Tools to decode tyre markings, compare sizes and plan costs, with guidance on using the results.
Choose a calculator below. Each explains its inputs, method and limitations, with no login required.
Axle load to load index
Enter an axle load, tyre quantity and margin to find the minimum load index for an initial comparison.
Open →Cost per kilometre — new against retread
Compare two tyre options using purchase price and expected service life, then estimate the annual difference across your fleet.
Open →Foam fill — weight and cost
Estimate foam fill volume, added weight and material cost from a tyre size. Use the result for initial planning and confirm the details with the fill contractor.
Open →Load index lookup
Look up the load capacity associated with a load index, and total it across a set of tyres.
Open →Rolling circumference & speedometer error
Compare nominal tyre dimensions and estimated rolling circumference between two sizes.
Open →Sidewall decoder
Decode tyre size and service markings into nominal dimensions, construction, load index and speed symbol.
Open →