Pressure Converter
Convert tyre pressure, weather pressure, blood-pressure units and engineering pressures between metric and imperial units.
Result
Enter a value to convert.
How to use this calculator
- Enter a pressure and choose the from and to units.
- Use the swap button to reverse.
- Gauge and absolute pressure are not converted into each other — see the limitations below.
Formula
Every unit is converted through pascals (1 Pa = 1 N/m²):
- 1 bar = 100,000 Pa
- 1 psi ≈ 6,894.757 Pa
- 1 standard atmosphere = 101,325 Pa = 760 mmHg
- 1 hPa = 1 mbar = 100 Pa
Worked example
Tyre pressure
32 psi × 6,894.757 ÷ 100,000 = 2.21 bar.
Standard atmosphere
1 atm = 1.01325 bar = 14.696 psi = 1,013.25 hPa.
Assumptions and limitations
- Gauge pressure (such as tyre pressure) is measured relative to the surrounding air; absolute pressure includes the atmosphere. Convert like with like.
- mmHg and inHg use standard conventional definitions.
Frequently asked questions
Is a millibar the same as a hectopascal?
Yes. 1 mbar = 1 hPa = 100 Pa, which is why weather maps use them interchangeably.
What does psig mean?
Pounds per square inch gauge — pressure above atmospheric. psia means absolute pressure.