Special Trailer (ST) Tire Load Rating & Cold Inflation Pressure Calculator
Calculate exact per-tire load, blowout safety reserve margin, and recommended cold inflation pressure (PSI / bar) for single, tandem, or triple axle trailers across Load Ranges C, D, E, and F.
Tire Load Safety Reserve Margin (%)
Calculator Inputs
Tire Load Safety Reserve Margin (%)
Actual Weight per Individual Tire
Recommended Cold Inflation Pressure (PSI)
Rated Tire Capacity
Actual Load per Tire vs Certified Maximum Rated Capacity (kg)
Tire and Rim Association (TRA) standards for Special Trailer (ST) designated tires. Maintain at least a 15% safety capacity buffer.
This calculator is designed for educational and informational purposes based on publicly declared statutory frameworks. The outputs do not constitute binding financial, tax, or legal advice. We assume no liability for decisions made based on these estimates. Always verify with the relevant official authorities or a certified professional advisor.
Calculation Methodology
Tire-Borne Weight = Gross Trailer Weight - Tongue Weight on Tow Vehicle. Load per Tire = Tire-Borne Weight / Total Trailer Tires. Safety Reserve % = ((Total Rated Capacity - Tire Weight) / Total Rated Capacity) * 100.
Frequently Asked Questions
Related Calculators
Recommended tools and calculators tailored to your current calculation