Pressure converter
Bar to Atmospheres
Converting Bar to Atmospheres is a single multiplication when you know the factor. One bar equals 0.98692327 atm, so multiply the value in bar by 0.98692327. The calculator below works in both directions and accepts decimals.
Formula 1 bar = 0.98692327 atm
Need the other direction? Atmospheres to Bar.
How to convert Bar to Atmospheres
One bar is exactly 100,000 pascals, slightly below standard atmosphere. Standard atmosphere is exactly 101,325 pascals.
To convert Bar to Atmospheres, multiply the value in bar by 0.98692327. For example, 10 bar × 0.98692327 = 9.869233 atm. This works because the ratio between the two units is constant for every value in pressure.
Worked examples
| bar | atm |
|---|---|
| 1 bar | 0.98692327 atm |
| 2.5 bar | 2.467308 atm |
| 5 bar | 4.934616 atm |
| 10 bar | 9.869233 atm |
| 25 bar | 24.673082 atm |
| 50 bar | 49.346163 atm |
| 100 bar | 98.692327 atm |
Reverse conversion
| atm | bar |
|---|---|
| 1 atm | 1.01325 bar |
| 5 atm | 5.06625 bar |
| 10 atm | 10.1325 bar |
| 25 atm | 25.33125 bar |
| 50 atm | 50.6625 bar |
| 100 atm | 101.325 bar |
When this conversion is useful
This is the calculation you need when you are inflating a tyre, reading a barometer or checking an engineering spec. Because the factor is fixed, you can use the same number for a single measurement or for a batch: 1,000 bar is 986.923267 atm.
Is the conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Reference: BIPM SI Brochure and NIST SP 811. Last reviewed: 2026-11-01.
bar to atm conversion chart
The chart lists the most requested values. For a value that is not here, use the converter at the top of the page.
| Bar (bar) | Atmospheres (atm) |
|---|---|
| 1 bar | 0.98692327 atm |
| 2 bar | 1.973847 atm |
| 3 bar | 2.96077 atm |
| 4 bar | 3.947693 atm |
| 5 bar | 4.934616 atm |
| 6 bar | 5.92154 atm |
| 7 bar | 6.908463 atm |
| 8 bar | 7.895386 atm |
| 9 bar | 8.882309 atm |
| 10 bar | 9.869233 atm |
| 11 bar | 10.856156 atm |
| 12 bar | 11.843079 atm |
| 13 bar | 12.830002 atm |
| 14 bar | 13.816926 atm |
| 15 bar | 14.803849 atm |
| 16 bar | 15.790772 atm |
| 17 bar | 16.777696 atm |
| 18 bar | 17.764619 atm |
| 19 bar | 18.751542 atm |
| 20 bar | 19.738465 atm |
| 21 bar | 20.725389 atm |
| 22 bar | 21.712312 atm |
| 23 bar | 22.699235 atm |
| 24 bar | 23.686158 atm |
| 25 bar | 24.673082 atm |
| 26 bar | 25.660005 atm |
| 27 bar | 26.646928 atm |
| 28 bar | 27.633851 atm |
| 29 bar | 28.620775 atm |
| 30 bar | 29.607698 atm |
| 31 bar | 30.594621 atm |
| 32 bar | 31.581545 atm |
| 33 bar | 32.568468 atm |
| 34 bar | 33.555391 atm |
| 35 bar | 34.542314 atm |
| 36 bar | 35.529238 atm |
| 37 bar | 36.516161 atm |
| 38 bar | 37.503084 atm |
| 39 bar | 38.490007 atm |
| 40 bar | 39.476931 atm |
| 41 bar | 40.463854 atm |
| 42 bar | 41.450777 atm |
| 43 bar | 42.4377 atm |
| 44 bar | 43.424624 atm |
| 45 bar | 44.411547 atm |
| 46 bar | 45.39847 atm |
| 47 bar | 46.385394 atm |
| 48 bar | 47.372317 atm |
| 49 bar | 48.35924 atm |
| 50 bar | 49.346163 atm |
| 60 bar | 59.215396 atm |
| 70 bar | 69.084629 atm |
| 80 bar | 78.953861 atm |
| 90 bar | 88.823094 atm |
| 100 bar | 98.692327 atm |
Frequently asked questions
How many Atmospheres are in 1 Bar?
1 bar equals 0.98692327 atm.
How do I convert Bar to Atmospheres?
Multiply the bar value by 0.98692327. Example: 25 bar = 24.673082 atm.
What is 2.5 bar in atm?
2.5 bar = 2.467308 atm.
Is the bar to atm conversion exact?
Yes for practical use: the factors come from international definitions, with rounding applied only for display.
Does the calculator work offline?
Yes. The conversion runs in your browser with JavaScript, so it works after the page has loaded, even without a connection.