Pressure Converter
Convert between Pa, kPa, MPa, bar, psi, atm, and mmHg — live update.
Frequently asked questions
What is standard atmospheric pressure?
Standard atmosphere (1 atm) is exactly 101,325 Pa — the average air pressure at sea level. This is the baseline for many engineering calculations and altitude definitions. At the top of Everest (~8,849 m), atmospheric pressure is roughly 0.34 atm (34 kPa).
What is psi used for?
PSI (pounds per square inch) is the standard pressure unit in the US for everyday applications: tyre pressure (typically 30–35 psi), blood pressure (120/80 mmHg ≈ 2.3 psi), compressed air tools, and water pressure. It is rarely used outside the US and UK.
What is the difference between mmHg and Torr?
mmHg (millimetres of mercury) and Torr are very nearly equal — 1 Torr = 1/760 atm, while 1 mmHg = 133.322 Pa. They differ by less than 0.000015%. For all practical purposes they are interchangeable and are both used in medicine for blood pressure measurement.
