What this calculator does
Tyre pressure is measured in kilopascals on most placards outside North America and in PSI (pounds per square inch) on most placards in the United States, so a tyre spec sheet or manual quoting one unit often needs converting to check against a gauge reading in the other. The conversion factor is fixed: 1 kPa equals 0.145038 PSI.
Getting tyre pressure wrong in either direction has real consequences: underinflated tyres run hot, wear unevenly on the edges and increase fuel use, while overinflated tyres wear the centre of the tread and reduce grip. Because the correct pressure is usually specified to the nearest 5 or 10 kPa (or whole PSI), a precise conversion matters more here than it does for many other unit conversions.
The formula
To convert kPa to PSI, multiply by 0.145038. To convert PSI to kPa, divide by the same factor. The equivalent in bar is shown alongside, since bar is a third unit sometimes used on pressure gauges, where 1 bar equals exactly 100 kPa.
| Term | Meaning |
|---|---|
| kPa (kilopascal) | The metric pressure unit used on most tyre placards outside North America. |
| PSI (pounds per square inch) | The imperial pressure unit used on most tyre placards and gauges in the United States. |
| bar | A third common pressure unit, exactly 100 kPa, sometimes marked on tyre gauges and compressors. |
The inputs explained
| Field | What to enter |
|---|---|
| Direction | Choose from kPa to PSI, PSI to kPa. |
| Tyre pressure | Enter the tyre pressure value, in kPa or PSI depending on the direction selected above. |
When to use it
Checking a US-spec vehicle against a metric gauge
A door-jamb placard quoting PSI needs converting to kPa if the only pump or gauge available reads in kilopascals, or vice versa.
Comparing pressure across regions
Recommended tyre pressures for the same vehicle model are sometimes published in kPa in one market and PSI in another; converting both to the same unit confirms they actually match.
Reading a compressor or gauge in bar
Some workshop gauges and compressors are calibrated in bar rather than kPa or PSI; the bar figure shown alongside the main result covers that case without a separate lookup.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
What do common kPa tyre pressures read in PSI?
A range of kPa values often seen on tyre placards, converted to PSI and bar.
| Pressure (kPa) | Tyre pressure in PSI | Tyre pressure in bar |
|---|---|---|
| 180 kPa | 26.1 psi | 1.80 bar |
| 200 kPa | 29.0 psi | 2.00 bar |
| 220 kPa | 31.9 psi | 2.20 bar |
| 230 kPa | 33.4 psi | 2.30 bar |
| 250 kPa | 36.3 psi | 2.50 bar |
| 280 kPa | 40.6 psi | 2.80 bar |
What do common PSI tyre pressures read in kPa?
A range of PSI values often seen on US tyre placards, converted to kPa and bar.
| Pressure (PSI) | Tyre pressure in kPa | Tyre pressure in PSI |
|---|---|---|
| 26 psi | 179 kPa | 26.0 psi |
| 30 psi | 207 kPa | 30.0 psi |
| 32 psi | 221 kPa | 32.0 psi |
| 35 psi | 241 kPa | 35.0 psi |
| 36 psi | 248 kPa | 36.0 psi |
| 40 psi | 276 kPa | 40.0 psi |
Questions
What is the exact conversion factor?
1 kPa equals 0.145038 PSI, and 1 PSI equals 6.894757 kPa. These are fixed unit-conversion factors, not approximations that vary by tyre or vehicle.
Should I use the pressure on the tyre sidewall or the door placard?
The door placard (or fuel-flap sticker or owner's manual) gives the pressure recommended for that specific vehicle, and is the figure to use. The number moulded into the tyre sidewall is the maximum pressure the tyre itself is rated for, not the recommended running pressure.
Does tyre pressure need adjusting for temperature?
Yes. Tyre pressure rises as the air inside heats up, including simply from driving. Pressure should be checked and set when tyres are cold, meaning the vehicle has not been driven for at least a few hours, for an accurate reading.
How is this different from a general pressure converter?
The underlying kPa-to-PSI factor is the same one used in any pressure conversion, including the site's general pressure converter. This page is framed specifically around tyre pressure values and ranges, since that is the most common reason people look up this particular conversion.
For pressure conversions across other units such as atmospheres, bar and millimetres of mercury, see the pressure converter. For a look at pressure in a fluid column context, see the related pressure calculators on this site.