PSI to kPa Converter
Convert pounds per square inch to kilopascals instantly
Pressure Conversion
Conversion Result
What are PSI and kPa?
PSI (Pounds per Square Inch)
PSI is an imperial unit of pressure measuring the force applied in pounds over one square inch of area. Widely adopted in the United States and the United Kingdom, PSI remains the standard for tyre pressure specifications, hydraulic systems, and industrial machinery. Most vehicle manufacturers list tyre pressures between 30 and 35 PSI for passenger cars.
kPa (Kilopascals)
The kilopascal is a metric unit where one kPa equals 1,000 Pascals. Named after French mathematician Blaise Pascal, this SI-derived unit measures internal pressure, stress, and tensile strength. European vehicle manufacturers typically specify tyre pressures in the range of 200 to 250 kPa, which corresponds to the 30-35 PSI range.
Conversion Formula & Method
PSI to kPa Formula:
kPa to PSI Formula:
Conversion Steps
- Identify your starting value – Determine whether you have a PSI or kPa measurement
- Apply the conversion factor – Multiply PSI by 6.89476 to get kPa, or divide kPa by 6.89476 to get PSI
- Round appropriately – For tyre pressure, rounding to 1-2 decimal places is typically sufficient
- Verify the result – Check that your converted value falls within expected ranges
Common PSI to kPa Values
This table shows frequently encountered tyre pressure conversions for cars, motorcycles, and light commercial vehicles.
| PSI | kPa | Bar | Common Application |
|---|---|---|---|
| 20 | 137.90 | 1.38 | Under-inflated tyre |
| 25 | 172.37 | 1.72 | Bicycle tyre (low pressure) |
| 30 | 206.84 | 2.07 | Standard car tyre |
| 32 | 220.63 | 2.21 | Recommended car tyre |
| 35 | 241.32 | 2.41 | Fully loaded vehicle |
| 40 | 275.79 | 2.76 | Light commercial vehicle |
| 45 | 310.26 | 3.10 | Van or lorry (front) |
| 50 | 344.74 | 3.45 | Heavy-duty application |
| 60 | 413.69 | 4.14 | Commercial vehicle (rear) |
| 65 | 448.16 | 4.48 | Motorcycle tyre |
| 80 | 551.58 | 5.52 | High-performance tyre |
| 100 | 689.48 | 6.89 | Industrial equipment |
Typical Tyre Pressure Ranges
Compare standard pressure recommendations across different vehicle types.
Passenger Car
207-241 kPa
SUV / 4×4
221-276 kPa
Light Van
276-345 kPa
Motorcycle
193-290 kPa
Bicycle (Road)
552-896 kPa
Commercial Lorry
517-758 kPa
Why Convert Between PSI and kPa?
Different regions and industries prefer specific pressure units. The UK automotive sector predominantly uses PSI for tyre specifications, whilst European manufacturers often list pressures in kPa or bar. Converting between these units becomes essential when:
- Purchasing imported vehicles with metric specifications
- Inflating tyres at petrol stations with metric-only gauges
- Following manufacturer recommendations from different markets
- Working with international technical documentation
- Comparing pressure specifications across regions
- Servicing hydraulic or pneumatic systems with mixed equipment
Pressure Measurement in the UK
Although the United Kingdom officially adopted the metric system in 1965, PSI remains dominant for tyre pressure applications. Most UK drivers recognise PSI values, and the majority of pressure gauges sold in British automotive retailers display PSI prominently. However, European vehicle imports increasingly show kPa specifications on door jamb stickers, requiring motorists to convert or reference dual-unit gauges.
The UK tyre industry recommends checking pressure monthly and before long journeys. Correct inflation improves fuel efficiency by up to 3%, extends tyre life, and enhances vehicle safety. Whether your gauge reads PSI or kPa, maintaining manufacturer-specified pressures remains critical for optimal performance.
Extended Conversion Reference
Comprehensive PSI to kPa conversion values from 1 to 150 PSI.
| PSI | kPa | PSI | kPa | PSI | kPa |
|---|---|---|---|---|---|
| 1 | 6.89 | 26 | 179.26 | 75 | 517.11 |
| 2 | 13.79 | 28 | 193.05 | 80 | 551.58 |
| 3 | 20.68 | 29 | 199.95 | 85 | 586.05 |
| 4 | 27.58 | 30 | 206.84 | 90 | 620.53 |
| 5 | 34.47 | 32 | 220.63 | 95 | 655.00 |
| 10 | 68.95 | 34 | 234.42 | 100 | 689.48 |
| 12 | 82.74 | 35 | 241.32 | 110 | 758.42 |
| 14 | 96.53 | 36 | 248.21 | 120 | 827.37 |
| 15 | 103.42 | 38 | 262.00 | 130 | 896.32 |
| 18 | 124.11 | 40 | 275.79 | 140 | 965.27 |
| 20 | 137.90 | 45 | 310.26 | 150 | 1034.21 |
| 22 | 151.68 | 50 | 344.74 | 200 | 1378.95 |
| 24 | 165.47 | 60 | 413.69 | 250 | 1723.69 |
| 25 | 172.37 | 70 | 482.63 | 300 | 2068.43 |
Frequently Asked Questions
How many kPa equal 1 PSI?
One pound per square inch equals precisely 6.89476 kilopascals. For practical purposes, you can use the rounded factor of 6.895 when converting tyre pressures or general applications.
Is 220 kPa the same as 32 PSI?
Yes, 220 kPa converts to approximately 31.9 PSI, which rounds to 32 PSI. This is one of the most common tyre pressure specifications for passenger vehicles in both metric and imperial markets.
Which pressure unit is more accurate?
Both units offer equal accuracy when measured correctly. The Pascal (and kilopascal) is the SI standard, making it scientifically preferred, but PSI remains practical and widely understood in the UK and US automotive industries.
Should I inflate my tyres to PSI or kPa specifications?
Follow the unit shown on your vehicle’s tyre placard, typically located on the driver’s door jamb. If your pressure gauge displays a different unit, convert the manufacturer’s specification before inflating. Both units are equally valid when properly converted.
What is the relationship between kPa and bar?
One bar equals 100 kilopascals exactly. Therefore, 1 PSI equals approximately 0.0689476 bar. Many European pressure gauges display both bar and kPa, whilst UK gauges typically show PSI and sometimes bar.
How do I check tyre pressure correctly?
Check tyre pressure when tyres are cold (driven less than 2 miles), as driving heats tyres and increases pressure readings by 2-4 PSI (14-28 kPa). Remove the valve cap, press the gauge firmly onto the valve stem, and read the measurement quickly.
What happens if I use the wrong pressure unit?
Confusing units can lead to severe under-inflation or over-inflation. For example, inflating to 35 kPa instead of 35 PSI would leave tyres dangerously under-inflated at only 5 PSI. Always verify which unit your gauge displays before inflating.
Do all countries use the same pressure units?
No. The United States and UK primarily use PSI, continental Europe uses bar and kPa, whilst some Asian markets use kg/cm². Modern vehicles sold internationally often display specifications in multiple units to accommodate different markets.