TireSize tire pressure calculator
Set the right PSI before every drive or ride.
The TireSize tire pressure calculator accounts for tire width, casing type, load, and rim design so you know how far to adjust from factory values when you change tires or carry extra weight.
Automotive Tire Pressure Calculator
Adjust PSI when changing tire load index or size
Original Equipment (OEM)
Found on sidewall (e.g. 205/55R16 91V)
Drivers door jamb sticker
New Tire Setup
Index of the new tires you are installing
Recommended Cold Pressure
To carry the equivalent load of 1262 lbs
How to use the Tire Load Index Calculator
- Find the Original Load Index and recommended pressure on your drivers door placard (e.g., 91 and 32 psi).
- Enter the New Load Index of the tires you plan to install (e.g., 94).
- The calculator determines the exact adjusted pressure needed for the new tire to carry the same vehicle weight safely.
Why this matters: If your new tires have a different load index, sticking to the factory PSI might lead to under-inflation (unsafe) or over-inflation (uneven wear). Use this tool to find the new "Goldilocks" pressure.
Changing Tire Size?
When changing size, the new tire often has a different air volume and load capacity. This calculator helps you re-calibrate PSI to keep the load limit identical to factory specs.
Switching to XL / Reinforced?
Extra Load (XL) tires require higher pressure to achieve their max load rating. This tool adjusts for the specific load curve of your new set.
Safety First
Never exceed the max pressure listed on the tire sidewall. This calculator provides a target for daily driving load capacity, not maximum inflation.
TireSize tire pressure FAQ
Stay safe, stay efficient
How does load index affect tire pressure?+
The load index tells you how much weight a tire can carry at a specific pressure. If you switch to a tire with a different index, you must adjust the pressure to maintain the same load-carrying capacity as your factory tires.
What happens if I use a lower load index tire?+
It is generally unsafe to use a tire with a lower load index than your OEM tires. If you do, you must significantly increase tire pressure to carry the same weight, but you cannot exceed the max sidewall pressure.
Why did the calculator suggest a higher pressure for my new tires?+
If your new tires have a lower load index or are XL (Extra Load) rated but used at lower pressures, they may need more PSI to support the same vehicle weight as your original set.
Should I ever go below the door placard pressure?+
Rarely. If you install significantly larger tires (e.g., off-road 35s on a Jeep), they might carry the weight at lower PSI, but you must ensure the TPMS system is recalibrated and handling is not compromised.
Disclaimer
The calculations and recommendations on this site are for informational purposes only. Always consult your vehicle manufacturer, tire professional, and local regulations before making any changes to tire or wheel size.