What this converter does
This converter turns pressure between psi, bar, megapascals, kilopascals, atmospheres, millimetres of mercury and millibars — instantly and with exact factors. Type a value, pick the units, and the answer updates as you type. Handy for reading US gauges into metric units.
One psi is about 0.06895 bar, so 14.504 psi make a bar. Bar is close to one atmosphere but not identical (1 atm = 14.696 psi). For materials and high-pressure work, the MPa option is often more convenient.
The units it covers
Every unit measures pressure, so each converts through the pascal with a fixed ratio.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Pound per square inch | psi | 6894.76 | US pressure, tyres, tanks |
| Bar | bar | 100000 | Tyres, hydraulics, weather |
| Megapascal | MPa | 1000000 | Materials, high pressure |
| Kilopascal | kPa | 1000 | SI everyday pressure |
| Atmosphere | atm | 101325 | Reference standard pressure |
| Millimetre of mercury | mmHg | 133.322 | Vacuum, blood pressure |
| Millibar | mbar | 100 | Meteorology, low pressure |
The formula
Each unit has a fixed value in pascals, so any conversion goes through the pascal once:
result = value × factor_from ÷ factor_toWhere:
- value = the number you typed, in the “from” unit
- factor_from = the “from” unit’s value in pascals
- factor_to = the “to” unit’s value in pascals
Worked example
Convert 30 psi to bar.
psi = 6894.757 Pa · bar = 100000 Pa30 × 6894.757 ÷ 100000 = 2.068 barSo 30 psi is about 2.07 bar — a typical tyre pressure.
The units in this example
An imperial pressure unit — one pound-force per square inch. Standard for US tyres, tanks and pneumatic systems.
- 1 psi ≈ 6894.76 Pa
- 1 psi ≈ 0.06895 bar
- 1 psi ≈ 6.895 kPa
- 14.504 psi = 1 bar
A metric pressure unit equal to exactly 100,000 pascals, close to one atmosphere. Common for tyres, hydraulics and weather.
- 1 bar = 100,000 Pa
- 1 bar ≈ 14.504 psi
- 1 bar = 100 kPa
- 1 bar ≈ 0.987 atm