Standard atmospheres: conversions & definition
One standard atmosphere is defined as 101,325 pascals. It is a reference unit, not a statement of the actual atmospheric pressure at your location.
Choose the unit you need
Each row converts one atm. Open a converter to enter any value and see its formula, worked example and reference table. Results below are rounded to 10 significant digits.
| Convert to | Equivalent value | Calculator |
|---|---|---|
| Pascals (Pa) | ≈ 101,325 | Convert atm to Pa |
| Kilopascals (kPa) | ≈ 101.325 | Convert atm to kPa |
| Megapascals (MPa) | ≈ 0.101325 | Convert atm to MPa |
| Bar (bar) | ≈ 1.01325 | Convert atm to bar |
| PSI (psi) | ≈ 14.69594878 | Convert atm to psi |
Keep the quantity consistent
Choose units that represent the same quantity and preserve the measurement conditions. A scale conversion changes the number and unit together; it does not change the physical amount or improve the accuracy of your measurement.
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