PRACTICAL GUIDE
Tyre pressure: PSI, bar and kPa explained
PSI, bar and kPa are three ways of expressing the same pressure. Converting between them does not tell you what pressure your car needs: find that recommendation in your vehicle handbook or on its pressure placard first.
Tyre pressure converter
Enter a pressure and its unit. Results are conversions, not recommended tyre settings.
What each unit means
| Unit | Meaning | Relationship |
|---|---|---|
| PSI | Pounds-force per square inch | 1 PSI ≈ 6.894757 kPa |
| bar | A metric pressure unit | 1 bar = 100 kPa |
| kPa | Kilopascals | 100 kPa ≈ 14.5038 PSI |
The units do not determine gauge quality. A poor gauge remains inaccurate when switched from PSI to bar. Use the unit shown in your vehicle documentation to reduce conversion mistakes.
Common pressure conversions
| PSI | bar | kPa |
|---|---|---|
| 30 | 2.068 | 206.84 |
| 32 | 2.206 | 220.63 |
| 35 | 2.413 | 241.32 |
| 40 | 2.758 | 275.79 |
These are examples, not suggested settings. Values are rounded. Match your actual vehicle recommendation and do not treat extra decimal places as evidence of gauge precision.
Where to find the right tyre pressure
Use the vehicle handbook or pressure placard, often in the door opening or fuel flap. Check the tyre size and load condition. Front and rear pressures may differ. Do not substitute the tyre sidewall maximum for the vehicle’s recommended operating pressure.
How to convert without the tool
- PSI to kPa: multiply by 6.894757.
- kPa to bar: divide by 100.
- bar to PSI: multiply by 100, then divide by 6.894757.
For example, 2.4 bar is approximately 34.81 PSI. A displayed value of 35 PSI is a rounded conversion, not a new recommendation.
Cold pressure, warm pressure and TPMS
Check tyres cold where possible. Pressure rises as tyres warm, so do not bleed a warm tyre down to the cold specification simply because its reading is higher. Recheck cold and follow the vehicle’s guidance.
Check at least monthly and before long journeys, even with TPMS. A warning light should prompt investigation; it is not a substitute for regular checks.
Frequently asked questions
What is 32 PSI in bar?
32 PSI is approximately 2.206 bar, or 220.63 kPa. This is a conversion, not a recommended pressure for every car.
Is 2.4 bar the same as 35 PSI?
2.4 bar is approximately 34.81 PSI, which rounds to 35 PSI. Use the manufacturer’s stated unit and setting when possible.
Is bar more accurate than PSI?
No. The unit is a scale. Accuracy depends on the measuring instrument and how it is used.
Sources & further reading
- TyreSafe — finding vehicle pressure settings ↗
- TyreSafe — pressure-check frequency and TPMS ↗
- Michelin — inflating tyres ↗
- NIST — pressure unit conversions ↗
Editorial review: 13 October 2026. Manufacturer claims remain attributed; specifications can change.