Free tool
Tire pressure calculator
Is your cold tire pressure still right? Start with the front and rear numbers on your driver’s door sticker (B-pillar). We’ll nudge for who’s riding, outdoor temp, and the road you’re on — optional sidewall details if you have them. When you’re unsure, the placard still wins.
Quick FAQ
- Should I set cold or hot tire pressure?
- Always set pressure when tires are cold — before a long drive, or after the vehicle has sat at least three hours. The “at today’s temp” figure is only a rough ambient adjustment vs 68°F (about +1 PSI per 10°F). It is not post-drive heat, and you should not deflate a hot tire down to the placard.
- Why enter front and rear placard PSI separately?
- Many U.S. door stickers list different cold pressures for the front and rear axles (and sometimes a higher figure for full load). This tool computes each axle from its own placard value.
- What do load index and speed rating do here?
- They do not replace the placard. Load index is used for a capacity headroom check (shown in pounds, like the sidewall max-load marking); speed rating mainly warns on sustained interstate use with a low rating. Both may add a small bounded offset — still capped by sidewall max when you enter it.
- Where do I find placard PSI, load index, speed rating, and tire age?
- Placard: driver’s door jamb (B-pillar) sticker. Load index and speed rating are molded on the sidewall after the size (e.g. 255/55R18 109V → LI 109, speed V). Tire age: the DOT TIN’s last four digits are week + year (e.g. 2321 = week 23 of 2021). Do not use the sidewall max PSI as your daily target.
- What if I am not sure about a field?
- Leave sidewall fields blank or on “Not sure” under Tire sidewall details. Essentials (placard, load, temp, road, driving style) are enough for a placard-first recommendation. Use Reset to restore the starting defaults.