Pressure Converters
Pressure is reported in a wide range of units depending on the field: pascals and bars in engineering, psi for tires and compressors in the US, atmospheres in chemistry and millimeters of mercury in medicine. Converting wrongly can be costly or unsafe, for example when inflating a tire or setting a regulator, so these converters use the exact defined factors and show them on the page.
All pressure converters
Atmospheres to Pascals1 atm = 101,325 PaBars to Pounds per Square Inch1 bar = 14.5038 psiKilopascals to Pounds per Square Inch1 kPa = 0.145038 psiMillimeters of Mercury to Kilopascals1 mmHg = 0.133322 kPaPounds per Square Inch to Bars1 psi = 0.0689476 barPounds per Square Inch to Pascals1 psi = 6,894.76 Pa
Things to know about pressure conversions
- Gauge pressure (what a tire gauge shows) excludes the surrounding atmosphere, while absolute pressure includes it. Check which one a spec means before converting.
- One bar is 100,000 pascals, close to one atmosphere (101,325 Pa). One psi is about 6.895 kPa.
- Blood pressure is measured in millimeters of mercury (mmHg). 120 mmHg is about 16 kPa.
Pressure conversion chart
Read across: one of the unit in the left column equals the value shown under each unit.
| 1 unit = | Pa | kPa | bar | psi | atm | mmHg |
|---|---|---|---|---|---|---|
| Pa | 1 | 0.001 | 0.00001 | 0.000145 | 9.869 × 10-6 | 0.007501 |
| kPa | 1,000 | 1 | 0.01 | 0.145 | 0.009869 | 7.501 |
| bar | 100,000 | 100 | 1 | 14.5 | 0.9869 | 750.1 |
| psi | 6,895 | 6.895 | 0.06895 | 1 | 0.06805 | 51.71 |
| atm | 101,325 | 101.3 | 1.013 | 14.7 | 1 | 760 |
| mmHg | 133.3 | 0.1333 | 0.001333 | 0.01934 | 0.001316 | 1 |
Pressure units explained
- Pascal (Pa)
- The pascal is the SI unit of pressure: one newton per square meter. It is a very small unit, so kilopascals are more common.
- Kilopascal (kPa)
- A kilopascal is 1,000 pascals. Tire pressures and weather barometers are often given in kPa.
- Bar (bar)
- A bar is exactly 100,000 pascals, close to atmospheric pressure at sea level. It is used for tires, diving and industrial gauges.
- Pound per square inch (psi)
- Psi is the pressure from one pound-force on one square inch, about 6,894.76 pascals. It is the standard for tires and air tools in the US.
- Standard atmosphere (atm)
- One atmosphere is exactly 101,325 pascals, the average air pressure at sea level.
- Millimeter of mercury (mmHg)
- A millimeter of mercury is about 133.32 pascals. It is the unit blood pressure is measured in.