Instantly convert between Pa, kPa, MPa, bar, psi, atm, mmHg, and torr
Pressure is defined as force per unit area. Different fields and regions around the world use various units to measure pressure, which can make conversions essential for engineering, science, medicine, and everyday applications. Our converter supports all major pressure units used globally.
The Pascal (Pa) is the SI unit of pressure, named after mathematician Blaise Pascal. One Pascal equals one Newton per square meter (N/m²). Kilopascals (kPa) and megapascals (MPa) are commonly used for engineering applications, with 1 MPa equal to 1,000,000 Pa or 1,000 kPa.
The bar is widely used in engineering and meteorology, particularly in Europe. One bar equals 100,000 Pa, very close to atmospheric pressure (1 atm = 1.01325 bar). PSI (pounds per square inch) remains standard in the United States and UK for tire pressure, hydraulics, and industrial applications.
Atmospheric pressure at sea level is defined as 1 atm, which equals 101,325 Pa or 760 mmHg. The mmHg unit, also known as torr after Evangelista Torricelli, is commonly used in medicine for measuring blood pressure and in laboratories for vacuum measurements.
| Unit | To Pascal | From Pascal |
|---|---|---|
| Pa | 1 | 1 |
| kPa | × 1,000 | ÷ 1,000 |
| MPa | × 1,000,000 | ÷ 1,000,000 |
| bar | × 100,000 | ÷ 100,000 |
| psi | × 6,894.757 | ÷ 6,894.757 |
| atm | × 101,325 | ÷ 101,325 |
| mmHg | × 133.322 | ÷ 133.322 |
| torr | × 133.322 | ÷ 133.322 |
To convert PSI to bar, multiply the PSI value by 0.0689476. For example, 100 PSI equals 6.89476 bar. Alternatively, 1 bar = 14.5038 PSI.
1 Pascal equals 0.000145038 PSI. Since Pascal is a very small unit, it's often converted using kilopascals (1 kPa = 0.145 PSI). This is useful for tire pressure and engineering calculations.
1 atm (atmosphere) equals exactly 760 mmHg or 760 torr. This is the standard atmospheric pressure at sea level, used as a reference in many scientific and medical applications including blood pressure measurement.
Torr and mmHg are essentially identical units with less than 0.0001% difference. While mmHg is defined exactly as 1/760 atm (133.322368 Pa), torr is defined approximately as 1/760 of standard atmospheric pressure. For all practical purposes, 1 torr = 1 mmHg.
To convert kPa to MPa, divide the kPa value by 1,000. For example, 1000 kPa = 1 MPa. Both are SI-derived units: 1 MPa = 1,000,000 Pa and 1 kPa = 1,000 Pa, so 1 MPa = 1,000 kPa.
The bar is not part of the International System of Units (SI) because the SI unit for pressure is the Pascal. However, the bar is widely accepted for use alongside SI units because 1 bar is very close to 1 atm (1 bar = 0.986923 atm), making it practical for everyday use.