Atmospheres to Bars Converter
Enter the pressure in atmospheres below to convert it to bars.
Convert Atmospheres to Bars
Enter a value in atmospheres (atm) to convert to bars (bar).
Standard Atmosphere to Bar Conversion Table
Table showing various standard atmosphere measurements converted to bars. Click any preset value or arrow to load it into the converter.
| Atmospheres (atm) | Bars (bar) |
|---|---|
| 0.5 atm | 0.506625 bar |
| 1 atm | 1.01325 bar |
| 2 atm | 2.0265 bar |
| 5 atm | 5.06625 bar |
| 10 atm | 10.1325 bar |
| 15 atm | 15.19875 bar |
| 20 atm | 20.265 bar |
| 25 atm | 25.33125 bar |
| 30 atm | 30.3975 bar |
| 50 atm | 50.6625 bar |
How to Convert Atmospheres to Bars
To convert atmospheres to bars, multiply the pressure by the following conversion ratio: 1.01325 bars/standard atmosphere.
Since one standard atmosphere is equal to 1.01325 bars, you can use this simple formula to convert:
The pressure in bars is equal to the pressure in atmospheres multiplied by 1.01325.
For example, here's how to convert 1 atmospheres to bars using the formula above.
How Many Bars Are in a Standard Atmosphere?
There are 1.01325 bars in a standard atmosphere, which is why we use this value in the formula above.
Our standard atmosphere to bar calculator automatically converts your pressure measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Atmospheres and bars are both units used to measure pressure. Keep reading to learn more about each unit.
What Is a Standard Atmosphere?
A standard atmosphere is a unit of pressure equal to 101,325 pascals (Pa), the base unit for pressure. Standard sea-level atmospheric pressure defined as 101,325 Pascals. [1]
The standard atmosphere is classified as a standard unit of pressure. Atmospheres can be abbreviated as atm; for example, 1 standard atmosphere can be written as 1 atm.
When working with atmospheres (atm) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, atmospheres (atm) are widely used across large-scale industrial, bulk, and macro-level pressure specifications within international standard workflows, engineering documentation, and technical data sheets.
What Is a Bar?
A bar is a unit of pressure equal to 100,000 pascals (Pa), the base unit for pressure. Metric pressure unit equal to 100,000 Pascals (100 kPa). [2]
The bar is classified as a metric and SI-compatible unit of pressure. Bars can be abbreviated as bar; for example, 1 bar can be written as 1 bar.
When working with bars (bar) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, bars (bar) are widely used across large-scale industrial, bulk, and macro-level pressure specifications within SI metric workflows, engineering documentation, and technical data sheets.
When converting pressure between atmospheres (atm) and bars (bar), keep full floating-point precision (1 atm = 1.01325 bar; 1 bar = 0.9869233 atm) during intermediate calculations and round only the final bar figure to match your instrument tolerance.
More Standard Atmosphere & Bar Conversions
Need to calculate in the opposite direction? Use our bars to atmospheres converter (bar to atm) to switch your starting unit immediately. You can also explore related tools such as converting psi to bars, converting kilopascals to bars, or converting atmospheres to psi.
Convert from Atmospheres
Frequently Asked Questions
References
- [1]NIST SP 811 StandardNIST SP 811 (NIST SP 811 App. B.9 (Pressure & Stress))·Pressure Metrology Standard — Atmospheres (atm) to Bars (bar)
- [2]NIST CUU SpecificationNIST CUU (Derived SI Unit: Pascal (Pa))·Unit Specifications: Standard Atmosphere (atm) & Bar (bar)
- [3]BIPM ReferenceBIPM (SI Brochure (9th Ed.) — Mechanics)·Conversion Factors & Mathematical Basis (atm to bar)