Tire Pressure Estimator
Estimate the adjusted cold pressure for a new tire size. This is a general guide only — the only authoritative sources are your vehicle's door placard and the tire manufacturer's load/inflation table.
Disclaimer: This is an estimate only. Always follow the vehicle placard, tire manufacturer load tables and local regulations.
Original tire
205/55 R16
New tire
225/45 R17
Original load proxy
23114
New load proxy
22781
Estimated new PSI
33.5
Difference
+0.5 PSI
How the estimate works
The calculator uses a simple proxy for load capacity: load proxy = width × sidewall height. A larger proxy can support the same weight at lower pressure, so the adjusted pressure is original PSI × (old proxy ÷ new proxy).
Real tire engineering accounts for sidewall stiffness, ply rating, bead profile and exact load index — none of which the proxy captures. Use this as a sanity check, not as a setpoint.