Tyre pressure is quoted in different units around the world: in Europe usually bar, in the USA PSI, and some compressors also display kPa. Anyone bringing a tyre from the US or cycling across America needs to be able to convert. Our calculator does it instantly – and provides recommended values for your type of vehicle at the same time.
Step by Step: How to Use the Tyre Pressure Converter
- Enter the starting value: For example 32 for 32 PSI.
- Select the starting unit: PSI, bar or kPa.
- Select the target unit: For example bar.
- Result: 32 PSI = 32 / 14.504 = 2.21 bar.
- Look up the vehicle-specific recommendation: The correct pressure for your car is shown on a sticker inside the driver's door frame or on the fuel filler cap.
Practical Examples
Optimal car tyre pressure: Front axle typically 2.2–2.5 bar (32–36 PSI), rear axle 2.2–2.8 bar (higher when fully loaded). US tyre label showing 35 PSI = 35/14.504 = 2.41 bar.
Bicycle tyres: Road bike: 7–9 bar (100–130 PSI). Mountain bike off-road: 1.8–2.5 bar (26–36 PSI). Touring/hybrid bike: 4–5 bar (58–72 PSI).
Motorcycle: Front 2.2–2.5 bar (32–36 PSI), rear 2.5–2.9 bar (36–42 PSI) – varies by model and load. Always check cold tyres!
Tyre Pressure Conversion Factors
- 1 bar = 14.504 PSI = 100 kPa
- 1 PSI = 0.0690 bar = 6.895 kPa
- 1 kPa = 0.01 bar = 0.145 PSI
Recommended car range: 2.1–2.8 bar | Bicycle: 2.5–9 bar
Frequently Asked Questions (FAQ)
How often should I check tyre pressure?
At least once a month and before every long journey. With temperature changes: tyre pressure changes by about 0.1 bar for every 10°C difference. Check regularly in winter!
What happens with too low or too high tyre pressure?
Too low: increased wear on the shoulder area, worse steering and braking response, higher fuel consumption. Too high: harsher ride, uneven wear on the centre tread, increased risk of blowout in hot conditions.
When should I measure tyre pressure?
Always on cold tyres – after at least 2 hours of standing or no more than 3 km of driving. Warm tyres have higher pressure (which is correct), but this warm reading should not be deflated down to the cold recommended value.
