About this tool
Convert a pressure value between ten common units, entirely in your browser with nothing uploaded. Pick a From unit and a To unit, type a value, and the result updates live. The ⇄ button swaps the two units.
Every unit is defined by an exact factor to the SI base unit, the Pascal (Pa): the value is multiplied by the From factor to get Pascals, then divided by the To factor. For example 1 atm = 101325 Pa and 1 PSI = 6894.757293 Pa, so 1 atm = 101325 / 6894.757293 ≈ 14.6959 PSI.
Useful for tyres, weather, hydraulics, diving and vacuum work. Note that Torr and mmHg are treated as identical (1 Torr = 133.322368 Pa), and KSI is simply 1000 PSI.
Frequently asked questions
What base unit is used?
The Pascal (Pa). Each unit has an exact factor to Pascals, so conversions route through Pa: value × from-factor ÷ to-factor.
How many PSI is one atmosphere?
One standard atmosphere is 101325 Pa, which is about 14.6959 PSI. One bar (100000 Pa) is about 14.5038 PSI.
Are Torr and mmHg the same here?
Yes. This tool uses 1 Torr = 1 mmHg = 133.322368 Pa, the conventional millimetre-of-mercury value.
Is my input sent anywhere?
No. All maths runs locally in your browser with JavaScript; nothing is uploaded or stored.