Pressure
Convert standard atmosphere (atm) to megapascal (MPa). Pressure is force per unit area. Process engineers move constantly between SI (kPa, bar) and US (psi) units, and between absolute and gauge.
1 atm = 0.101325 MPa
To convert standard atmosphere to megapascal, multiply the atm value by 0.101325. To go the other way, divide by 0.101325 (or multiply by 9.869233).
| atm | MPa |
|---|---|
| 1 | 0.101325 |
| 2 | 0.20265 |
| 5 | 0.506625 |
| 10 | 1.01325 |
| 25 | 2.533125 |
| 50 | 5.06625 |
| 100 | 10.1325 |
| 250 | 25.33125 |
| 500 | 50.6625 |
| 1000 | 101.325 |
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 9.869233 atm is 1 MPa.
Multiply the value in atm by 0.101325 to get MPa. For example, 10 atm = 1.01325 MPa.
1 atm equals 0.101325 MPa.
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.