How to use
- Enter a pressure, then pick the unit you are converting from and the unit you want to.
- The result appears instantly, and the first table shows the same pressure in every unit.
- The last table shows familiar reference pressures — sea-level air, a car tire, a blood pressure reading — in whichever unit you picked.
Conversion factors
The pascal is one newton per square meter. Most pressure units are defined exactly in pascals.
| Unit | In pascals | Notes |
|---|---|---|
| 1 hPa (= 1 mbar) | 100 Pa | weather maps |
| 1 kPa | 1,000 Pa | tire pressure outside the US |
| 1 bar | 100,000 Pa | = 100 kPa |
| 1 atm | 101,325 Pa | standard atmosphere = 1,013.25 hPa |
| 1 psi | ≈ 6,894.757 Pa | one pound-force per square inch |
| 1 kgf/cm² | 98,066.5 Pa | older gauges, about 0.98 bar |
| 1 mmHg | 133.322387415 Pa | blood pressure |
| 1 torr | 101,325/760 ≈ 133.3224 Pa | vacuum work, nearly equal to mmHg |
| 1 inHg | ≈ 3,386.389 Pa | 25.4 mmHg, US aviation and weather |
Examples
- A tire inflated to 35 psi is at about 241.3 kPa or 2.41 bar.
- An altimeter setting of 29.92 inHg is 1,013.2 hPa — standard pressure.
- A blood pressure of 120 mmHg is about 16 kPa.
- A scuba tank filled to 200 bar holds about 2,900 psi.
Things to keep in mind
- Gauge vs absolute pressure. Tire and boiler gauges read zero at normal air pressure (gauge pressure, often written psig). Absolute pressure adds about 14.7 psi (101.3 kPa). This tool converts units only; it does not shift the zero point.
- mmHg and torr differ by about one part in seven million, so they are interchangeable in practice.
- Always use the tire pressure printed on your vehicle’s door jamb placard. For other unit types, try the unit converter.
FAQ
How many psi is one bar?
About 14.504 psi. To estimate, multiply bar by 14.5.
Is kgf/cm² the same as bar?
Close, but no: 1 kgf/cm² is 98,066.5 Pa, about 2% less than one bar.
What is standard atmospheric pressure?
Exactly 101,325 Pa — 1,013.25 hPa, 14.696 psi or about 760 mmHg.