Pressure
Convert pound per square inch (psi) to millibar (mbar). Pressure is force per unit area. Process engineers move constantly between SI (kPa, bar) and US (psi) units, and between absolute and gauge.
1 psi = 68.94757 mbar
To convert pound per square inch to millibar, multiply the psi value by 68.94757. To go the other way, divide by 68.94757 (or multiply by 0.01450377).
| psi | mbar |
|---|---|
| 1 | 68.94757 |
| 2 | 137.8951 |
| 5 | 344.7378 |
| 10 | 689.4757 |
| 25 | 1723.689 |
| 50 | 3447.378 |
| 100 | 6894.757 |
| 250 | 17236.89 |
| 500 | 34473.79 |
| 1000 | 68947.57 |
Line and vessel ratings, pump discharge heads, and relief set points are all specified in pressure units — usually psi or barg in the field and kPa in calculations.
Always track whether a value is absolute or gauge: 0 barg equals about 101.3 kPa absolute, and mixing the two is a common and costly error.
Worked example. A pressure of 145.0377 psi is 10000 mbar.
Multiply the value in psi by 68.94757 to get mbar. For example, 10 psi = 689.4757 mbar.
1 psi equals 68.94757 mbar.
Line and vessel ratings, pump discharge heads, and relief set points are all specified in pressure units — usually psi or barg in the field and kPa in calculations.