Bar to Atmosphere Converter
Convert from Bar to Atmosphere (atm)
Understanding Bar and Atmosphere
The bar is a metric unit of pressure that is not part of the SI but is accepted for use with it.
- 1 bar = 100,000 pascals (Pa) = 100 kPa
- Approximately equal to atmospheric pressure at sea level
- Commonly used in meteorology and many engineering applications
The standard atmosphere (atm) is a unit of pressure defined as 101,325 pascals (101.325 kPa).
- Represents the average atmospheric pressure at sea level
- Not an SI unit but is accepted for use with the SI system
- Originally defined as the pressure exerted by 760 mm of mercury at 0°C and standard gravity
Conversion Formula
Bar to atm:
atm = bar × 0.9869
To convert from bar to atmospheres, multiply the bar value by approximately 0.9869.
atm to bar:
bar = atm × 1.01325
To convert from atmospheres to bar, multiply the atm value by approximately 1.01325.
Bar to Atmosphere Conversion Table
| Bar | Atmosphere (atm) |
|---|---|
| 0.2 | 0.1974 |
| 0.4 | 0.3948 |
| 0.6 | 0.5922 |
| 0.8 | 0.7895 |
| 1 | 0.9869 |
| 1.2 | 1.1843 |
| 1.4 | 1.3817 |
| 1.6 | 1.5791 |
| 1.8 | 1.7765 |
| 2 | 1.9738 |
Historical Context and Applications
Historical Development
The bar unit was introduced in 1909 by Norwegian meteorologist Vilhelm Bjerknes, and was originally defined as 1,000,000 dynes per square centimeter in the CGS system. The atmosphere (atm) as a unit has a much longer history, dating back to experiments by Evangelista Torricelli in the 17th century. The two units are closely related, with 1 atm being approximately equal to 1.01325 bar, showing the close relationship between atmospheric pressure and the bar unit.
Common Applications
- Bar: Widely used in meteorology, automotive applications, and industrial processes. The millibar (1/1000 of a bar) is frequently used in weather forecasting.
- atm: Often used in chemistry, particularly when discussing gas laws and partial pressures. Also used as a reference point in many scientific calculations.
Practical Examples
- Standard atmospheric pressure: 1.01325 bar (1 atm)
- Car tire pressure: 2.0-2.5 bar (1.97-2.47 atm)
- Bicycle tire pressure: 4-8 bar (3.95-7.9 atm)
- Espresso machine pressure: 9 bar (8.88 atm)
- Champagne bottle pressure: 5-6 bar (4.93-5.92 atm)
- Enter your value in the bar field
- The converter instantly displays the equivalent in atmospheres
- Use the swap button to convert from atmospheres to bar instead
- Results are displayed with 6 decimal places for precision
For quick reference without calculations, refer to the conversion table above for common values.