Pressure Converter
Free pressure converter: psi to bar, bar to kPa, atm to Pa, mmHg to kPa and torr. Exact definitions, an all-units table and a note on gauge versus absolute.
How to use Pressure Converter
- 1Enter a pressure, for example 5 or 32.
- 2Choose From and To units, such as bar to psi or mmHg to kPa.
- 3Check the factor line under the result, or open All units to see every pressure unit at once.
What makes it better
- Pa, kPa, MPa, bar, mbar, hPa, atm, psi, mmHg, torr and inHg
- Exact definitions for atm, bar and psi
- Torr and mmHg kept separate, since they differ slightly
- Convert mode plus All units table with copy buttons
About Pressure Converter
Pressure Converter changes values between pascal, hectopascal, kilopascal, megapascal, bar, millibar, standard atmosphere, psi, mmHg, torr and inches of mercury. The standard atmosphere (101,325 Pa), the bar (100,000 Pa) and the pound-force based psi are exact definitions, while mmHg and inHg use their conventional values. It converts the number you give; it does not add or remove atmospheric pressure.
Common uses
- Convert tyre pressure from psi to bar before inflating at a European petrol station.
- Read a blood-pressure value in mmHg as kilopascals for a medical paper.
- Compare a weather report in hPa with a barometer in inHg.
- Change a compressor or pump rating between bar, psi and MPa.
Example
Input
5
Result
5 bar ≈ 72.51886887 psi
Good to know
- Gauge versus absolute: the page converts the number you give. A gauge reading such as 32 psi does not include the roughly 14.7 psi (1.01325 bar) of atmosphere, so add it yourself if you need absolute pressure.
- mmHg uses the conventional 133.322387415 Pa and inHg 3,386.389 Pa. Torr is exactly 1/760 atm. mmHg and torr differ by roughly one part in seven million.
- psi is derived exactly from the international pound and inch, which gives 6,894.757293168… Pa; results are rounded and flagged accordingly.
Pressure Converter FAQ
How many psi are in a bar?
One bar is about 14.5037738 psi, so 5 bar is roughly 72.5189 psi. The factor is not a round number because the bar is metric (100,000 Pa) and the psi comes from pounds and inches.
How many kPa are in an atmosphere?
A standard atmosphere is exactly 101.325 kPa, which is also 1.01325 bar, 760 mmHg and about 14.696 psi. It is a defined reference value, not a measurement of today's weather.
How do I convert psi to kPa?
Multiply psi by about 6.894757. A typical 32 psi car tyre is therefore around 220.6 kPa or 2.21 bar. Choose psi as From and kPa as To to get the digits without rounding errors of your own.
Is mmHg the same as torr?
Almost, but not exactly. One torr is 1/760 of an atmosphere (133.3223684… Pa) and the conventional mmHg is 133.322387415 Pa. For blood pressure and most uses the difference is negligible.
What is a pascal?
A pascal is one newton of force per square metre, the SI unit of pressure. It is small, which is why everyday values use hPa for weather (about 1,013 hPa), kPa for tyres and MPa for hydraulics.