Commercial Truck Tire Load & Inflation Calculator

Correct tire inflation is the single most critical factor in commercial trucking safety and efficiency. Under-inflation leads to excessive heat buildup within the casing, causing structural fatigue and catastrophic blowouts. Conversely, over-inflation reduces the contact patch, leading to irregular wear and reduced traction. This tool calculates the required inflation pressure based on the specific load carried by the axle end, rather than the maximum rating stamped on the sidewall.

For heavy-duty applications, the relationship between load and pressure is not linear. It follows specific engineering curves defined by the Tire and Rim Association (TRA) or ETRTO standards. Accurate calculation prevents fuel wastage due to high rolling resistance and protects the casing for future retreading. Operators must account for the difference between Single and Dual fitment, as Dual configurations often have lower load capacities per tire to account for road camber and unequal load distribution.

The required inflation pressure P for a given load L is often approximated using the Load-Pressure ratio relative to the tire's maximum limits, though actual manufacturer tables are discrete steps. The basic engineering approximation is:

Where L_max is the maximum load rating at maximum pressure P_max. For dual assemblies, the maximum load L_dual is typically lower than single fitment L_single.

Safety margin S is applied to ensure pressure never drops below the minimum requirement during operation: