How to convert pressure
Pressure is force per unit area. The SI unit is the pascal (1 N/m²), which is tiny, so kilopascals, megapascals and bar are more common: 1 bar = 100,000 Pa = 100 kPa, close to atmospheric pressure at sea level (1 atm = 1.01325 bar = 14.696 psi).
- Bar to psi: multiply by 14.5038 (2.2 bar = 31.9 psi).
- Psi to kPa: multiply by 6.89476 (32 psi = 220.6 kPa).
- kgf/cm² to psi: multiply by 14.2233. Indian pressure gauges and tyre pumps often show kg/cm².
Everyday values: car tyres are usually 30–35 psi (2.1–2.4 bar). Blood pressure is measured in mmHg (120/80 mmHg). Weather maps use hectopascals or millibars, which are the same size: standard pressure is 1013.25 hPa.
Common pressure conversion factors
| Unit | Equals | Reverse |
|---|---|---|
| 1 bar | 14.50377377 psi | 1 pound per square inch = 0.0689475729 bar |
| 1 kilopascal | 0.1450377377 psi | 1 pound per square inch = 6.894757293 kPa |
| 1 standard atmosphere | 1,01,325 Pa | 1 pascal = 0.0000098692 atm |
| 1 millimetre of mercury | 0.1333223874 kPa | 1 kilopascal = 7.500615758 mmHg |
| 1 kilogram-force per cm² | 14.22334331 psi | 1 pound per square inch = 0.070306958 kgf/cm² |
| 1 megapascal | 145.0377377 psi | 1 pound per square inch = 0.0068947573 MPa |
| 1 inch of mercury | 33.86389 hPa | 1 hectopascal = 0.0295299802 inHg |
| 1 bar | 100 kPa | 1 kilopascal = 0.01 bar |
| 1 standard atmosphere | 1.01325 bar | 1 bar = 0.9869232667 atm |
Pressure conversions
Each of these has its own page with the formula, worked examples and a full conversion table:
All pressure units on this converter
| Unit | Symbol | 1 unit equals | System |
|---|---|---|---|
| Pascal | Pa | 1 Pa | Metric (SI) |
| Hectopascal | hPa | 100 Pa | Metric (SI) |
| Kilopascal | kPa | 1,000 Pa | Metric (SI) |
| Megapascal | MPa | 10,00,000 Pa | Metric (SI) |
| Bar | bar | 1,00,000 Pa | Metric (SI) |
| Millibar | mbar | 100 Pa | Metric (SI) |
| Kilogram-force per cm² | kgf/cm² | 98,066.5 Pa | Metric (SI) |
| Pound per square inch | psi | 6,894.757293 Pa | Imperial / US |
| Kilopound per square inch | ksi | 68,94,757.293 Pa | Imperial / US |
| Pound per square foot | psf | 47.88025898 Pa | Imperial / US |
| Standard atmosphere | atm | 1,01,325 Pa | Other |
| Torr | Torr | 133.3223684 Pa | Other |
| Millimetre of mercury | mmHg | 133.3223874 Pa | Other |
| Inch of mercury | inHg | 3,386.389 Pa | Other |
| Millimetre of water | mmH₂O | 9.80665 Pa | Other |
| Inch of water | inH₂O | 249.08891 Pa | Other |
Frequently asked questions
How many psi is 1 bar?
1 bar = 14.5038 psi. 1 psi = 0.0689476 bar.
Is kg/cm² the same as bar?
Almost: 1 kgf/cm² = 0.980665 bar (98.0665 kPa). They are often used interchangeably on gauges, but they are not identical.
What is atmospheric pressure in psi?
Standard atmospheric pressure is 14.696 psi = 101.325 kPa = 1.01325 bar = 760 mmHg.
Are hPa and mbar the same?
Yes. 1 hectopascal equals 1 millibar (100 Pa).