๐ก๏ธ Pressure Converter
Convert pressure units in real time โ pascals, atmospheres, bar, and psi. Useful for checking tire pressure, weather forecast barometric readings, or pressure specs for diving and mountaineering.
How to use
- Enter a value into any pressure unit field (Pa, kPa, hPa, bar, atm, psi, etc.).
- The other unit fields update with the converted value in real time.
- Enter a value from a foreign spec sheet to see it in a more familiar unit.
How the calculation works
Pressure is force per unit area. Its SI unit is the pascal (Pa = N/mยฒ), one newton spread over one square metre. That is small by everyday standards, so weather forecasts use the hectopascal (hPa, ร100) and tyre pressures the kilopascal (kPa). One standard atmosphere (atm) is defined as 101,325 Pa, roughly the average air pressure at sea level. A bar is 100,000 Pa, close to one atmosphere. A psi (pound per square inch) is about 6,894.76 Pa, and a millimetre of mercury (mmHg) about 133.32 Pa โ the unit used for blood pressure. Every conversion goes through pascals first, then back to the target unit.
Worked example
A recommended tyre pressure of 32 psi in kPa and bar kPa: 32 ร 6.894757 โ 220.6 kPa bar: 220.6 รท 100 โ 2.21 bar That matches the "220 kPa" printed inside the door of many Japanese cars. A blood pressure of 120 mmHg is 120 ร 133.322 โ 16.0 kPa.
Things to be aware of
- Tyre pressures are usually gauge pressure, measured relative to the surrounding air โ about 101 kPa below absolute pressure.
- Pressure rises with temperature, so check tyres cold, before driving.
- "kgf/cmยฒ" is an older unit: 1 kgf/cmยฒ โ 98.07 kPa.
- This tool only converts units; it does not work out, say, water pressure from depth.
FAQ
Can I convert tire pressure in psi to kPa?
Yes โ convert between psi and kPa/bar, handy for checking tire pressure specs from other countries.
Can it convert weather forecast hPa readings?
Yes โ convert between pascals/hectopascals and atmospheres, bar, and other pressure units.
Is this useful for bicycle tire pressure?
Yes โ psi, bar, and kPa all convert to each other, which helps when a pump gauge uses a different unit than the tire's rated pressure.
What is standard atmospheric pressure in other units?
1 atm equals about 101.325 kPa, 1013.25 hPa, or 14.696 psi. Enter 1 in the atm field to see each equivalent.
Can this help with water or gas pressure calculations?
This tool only performs unit conversion, not pressure calculations, but it's useful for viewing an already-calculated pressure value in a different unit.