Pressure Converter
How it works
Every value is turned into pascals first — multiplying by the entered unit's pascals-per-unit factor — and then divided back out by each of the six units' own factor. Pascal, kilopascal and bar are exact by their own definitions, one atmosphere is fixed at exactly 101,325 Pa by international convention, and PSI and torr use their standard rounded conversion constants (6894.76 Pa and 133.322 Pa). Going through one basis means all six answers on the page agree with each other by construction.
Because pressure has a real physical floor — an absolute pressure cannot be negative — a negative value is rejected here rather than converted, unlike a length or a signed delta that can legitimately go below zero.
Frequently asked questions
Where is each unit normally used?
PSI is the everyday unit for tire pressure in the US; bar is the equivalent everyday unit across most of Europe, for tires and often weather pressure too. Atmosphere is mainly used as a reference point rather than a reading. Pascal and kilopascal are the SI units, common in scientific work and some engineering contexts. Torr, also seen as mmHg, turns up in barometric readings and some medical pressure measurements.
Why is "1 atmosphere" the reference point for that unit specifically?
Because that is what it was defined to be: one standard atmosphere is fixed at exactly 101,325 Pa, chosen to represent typical average air pressure at sea level. It is a defined reference figure rather than a measurement of any one place or moment — actual sea-level pressure varies with weather from day to day.
Does temperature or altitude change these conversions?
No. This is a straightforward unit conversion — pascals, bar, PSI, atmospheres and torr all convert at a fixed ratio to each other regardless of conditions, the same way a mile is always 1.609 km whatever the weather is doing. What DOES change with temperature and altitude is the actual pressure being measured, not the arithmetic used to convert it between units.