Tire Pressure Calculator & Guide
Check if your tires are properly inflated — adjust the recommended pressure for temperature and hot tires, convert PSI, bar and kPa, and see typical pressures by vehicle type.
How to use
- 1Enter the recommended cold pressure from your door-jamb sticker.
- 2Enter the pressure you measured and whether the tires were cold or recently driven.
- 3See how much air to add or let out.
How it's calculated
Tire pressure changes about 1 PSI per 10 °F (0.1 bar per 10 °C). Driving warms tires and adds roughly 2–4 PSI, so recommended pressures are always 'cold' (parked 3+ hours).
Frequently asked questions
Where do I find my correct tire pressure?
On the sticker inside the driver's door jamb (or fuel flap / owner's manual) — not the 'max pressure' on the tire sidewall.
Why does my TPMS light come on in winter?
Cold air lowers pressure about 1 PSI per 10 °F drop. Top up to the recommended cold pressure when temperatures fall.
Is it bad to overinflate?
Slightly high pressure wears the center of the tread and reduces grip; low pressure wears the edges, hurts fuel economy and can overheat the tire.