Atmospheres to Bars
One atmosphere is the average air pressure at sea level, used as a reference unit in chemistry and physics. A bar is close to average atmospheric pressure at sea level, widely used for tire pressure and industrial gauges in Europe. 1 atm equals 1.01325 bar, so converting between them is a matter of multiplying by that fixed factor — type any value into the converter below and both sides update instantly as you type.
Both units belong to pressure, measured here against pressure's base unit (Pa) — every other pressure unit on this site converts through that same reference point, which is why the table below can also be read as a quick cross-check against nearby values.
Formula
bar = atm × 1.01325
atm = bar × ≈0.986923
Worked example: 5 atm × 1.01325 = 5.06625 bar.
Conversion table
| Atmosphere (atm) | Bar (bar) |
|---|---|
| 1 atm | 1.01325 bar |
| 2 atm | 2.0265 bar |
| 3 atm | 3.03975 bar |
| 5 atm | 5.06625 bar |
| 10 atm | 10.1325 bar |
| 20 atm | 20.265 bar |
| 25 atm | ≈25.3313 bar |
| 50 atm | 50.6625 bar |
| 100 atm | 101.325 bar |
| 250 atm | ≈253.313 bar |
| 500 atm | 506.625 bar |
| 1,000 atm | 1,013.25 bar |
Frequently asked
- How many Bars in a atmosphere?
- 1 atm equals 1.01325 bar.
- How do I convert Atmospheres to Bars?
- Multiply the value in atm by 1.01325 to get bar. The converter above does this instantly as you type.
- Is the conversion exact?
- Yes — Atmosphere and Bar are both defined by a fixed conversion factor to pressure's base unit (Pa), so the result shown is exact to the precision displayed, not an approximation.