Tire Pressure Converter
Convert tire pressure between PSI, bar, and kPa instantly.
Includes recommended pressure ranges for cars, bikes, and trucks.
Type in any field — the others update instantly.
Understanding Tire Pressure Units
Tire pressure is measured in three different units depending on your region and vehicle type. PSI (pounds per square inch) is standard in the United States and United Kingdom. Bar is used in most of continental Europe and many other countries. kPa (kilopascals) is the SI standard and is used in Australia, New Zealand, and appears on many international vehicle placards alongside PSI or bar.
Conversion Formulas:
1 PSI = 0.0689476 bar = 6.89476 kPa
1 bar = 14.5038 PSI = 100 kPa
1 kPa = 0.145038 PSI = 0.01 bar
These are exact conversions based on the definition of the pascal (1 Pa = 1 N/m2) and the pound-force per square inch.
Typical Tire Pressure Ranges:
| Vehicle Type | PSI | bar | kPa |
|---|---|---|---|
| Passenger car (front) | 30-35 | 2.1-2.4 | 207-241 |
| Passenger car (rear) | 30-35 | 2.1-2.4 | 207-241 |
| SUV / Crossover | 32-38 | 2.2-2.6 | 221-262 |
| Light truck | 35-45 | 2.4-3.1 | 241-310 |
| Heavy truck (steer) | 100-120 | 6.9-8.3 | 689-827 |
| Heavy truck (drive) | 90-110 | 6.2-7.6 | 621-758 |
| Road bicycle | 80-130 | 5.5-9.0 | 552-896 |
| Mountain bicycle | 25-40 | 1.7-2.8 | 172-276 |
| Motorcycle | 28-42 | 1.9-2.9 | 193-290 |
Why Tire Pressure Matters:
Correct tire pressure affects safety, fuel economy, and tire life. Even small deviations have significant effects:
- Underinflation (too low): Increases rolling resistance (more fuel consumption), causes uneven wear on the outer edges, generates excess heat (risk of blowout), and worsens handling and braking.
- Overinflation (too high): Causes wear in the center of the tread, reduces the contact patch (less grip), makes the ride harsh, and increases risk of damage from potholes or debris.
- A tire that is 20% underinflated can reduce tire life by 25% and increase fuel consumption by 2-3%.
Where to Find Your Recommended Pressure:
The correct tire pressure for your vehicle is NOT printed on the tire sidewall. The number on the tire (e.g., “Max 44 PSI”) is the maximum safe pressure for that tire, not the recommended operating pressure.
Your recommended pressure is found on:
- The driver’s side door jamb sticker
- The fuel filler door
- The owner’s manual
- Some glove box lids
Temperature Effects:
Tire pressure changes with temperature. For every 10F (5.5C) change in ambient temperature, tire pressure changes by approximately 1 PSI (0.07 bar / 6.9 kPa). Always check pressure when tires are cold (driven less than a mile or parked for 3+ hours).
Nitrogen vs Air:
Some shops fill tires with nitrogen instead of regular air. Nitrogen molecules are larger and leak more slowly, maintaining pressure longer. However, the difference is small for passenger vehicles. Regular air (which is already 78% nitrogen) works perfectly well with monthly pressure checks.