How to Use the Tire Pressure Temperature Change Calculator
Tire pressure changes with temperature due to Gay-Lussac's Law — as temperature drops, so does air pressure inside your tires. For every 10°F (about 5.5°C) decrease in temperature, tire pressure falls by approximately 1 PSI. This means tires properly inflated in summer can become underinflated in winter without any air loss.
Enter your current tire pressure, the temperature when you inflated it, and the current outside temperature. The calculator shows how much pressure has changed and whether you need to add or release air to reach the manufacturer's recommended PSI (found on your driver's side door jamb sticker).
Frequently Asked Questions
Underinflated tires wear unevenly, reduce fuel economy by up to 3%, and can overheat at highway speeds — increasing the risk of a blowout. Check your tire pressure monthly and whenever the temperature changes significantly.
Multiply PSI by 6.895 to get kPa. For example, 35 PSI = 241 kPa. Some European vehicles use bar: 1 bar = 14.5 PSI.