Pressure
Pascals, bar, PSI and atmospheres.
About Pressure
Convert pressure between pascals, kilopascals, bar, millibar, atmospheres, psi, mmHg and torr. Enter one value and every other unit is shown at once.
How to use
- Type a value and pick its unit. The default is 20 psi.
- Every other unit updates as you type; each row has its own Copy button, and Copy on the panel copies the whole table.
- Results are rounded to eight decimal places and formatted for your locale.
Conversion factors
All units convert through pascals:
| Unit | Pascals |
|---|---|
| kilopascal | 1 000 |
| millibar | 100 |
| bar | 100 000 |
| standard atmosphere | 101 325 |
| psi (pound-force per square inch) | 6 894.75729317 |
| mmHg | 133.322387415 |
| torr | 133.322387415 |
mmHg and torr share one factor here; the true definitions differ by less than one part in a million. The value must be greater than zero, so this tool converts absolute pressures, not gauge readings relative to atmosphere.
Example
20 psi → 137 895.1458634 Pa · 1.37895146 bar · 1.36091928 atm · 1 034.29850408 mmHg
Privacy
Runs in the browser. No request is made, and nothing is stored.
Frequently asked questions
- How many psi is 1 bar?
- About 14.504 psi. A bar is exactly 100,000 pascals, and one psi is 6,894.757 pascals. Tyre pressures of 2.2 bar and 32 psi are therefore nearly the same.
- What is the difference between bar and atm?
- A standard atmosphere is 101,325 Pa, about 1.3% more than a bar (100,000 Pa). 1 atm is 14.696 psi, 760 mmHg or 1,013.25 millibar, which is why weather maps centre around 1013 hPa.
- Are mmHg and torr the same?
- Almost. A torr is defined as 1/760 of a standard atmosphere (133.3224 Pa) and a millimetre of mercury as 133.3224 Pa based on mercury density; they differ by less than 0.0002%, so blood pressure and vacuum figures use them interchangeably.
- How do I convert kPa to psi?
- Divide by 6.895. A 250 kPa tyre is about 36.3 psi, and 100 kPa is 14.5 psi.