Convert atm to bar
Convert atm to bar instantly. 1 atm = 1.01325 bar. Formula, worked examples and a quick reference table.
Last updated
One atmosphere equals 1.01325 bars. To convert any number of atmospheres to bars, multiply by 1.01325.
The converter above works in both directions and updates as you type. Below you will find the formula, a worked example and a reference table of common values.
Pressure conversions are dominated by one everyday task: inflating a tyre. The United States and the United Kingdom quote psi, most of Europe uses bar, Canada and Australia use kilopascals, and the figure on the door jamb may not match the unit on the gauge. Beyond tyres, the same conversions serve weather reporting, diving, and any engineering work where a specification and an instrument were made in different markets.
atm to bar formula
To go the other way, use atmosphere = bar ÷ 1.01325.
About these units
The standard atmosphere is defined as exactly 101,325 pascals, the average sea-level air pressure. It is a useful reference precisely because it is close to what a person experiences.
One bar is 100,000 pascals, very close to average atmospheric pressure at sea level — which is why it was chosen.
Atmosphere is also written atmospheres. Bar is also written bars.
Sources
atm to bar conversion table
| Atmosphere | Bar |
|---|---|
| 1 atm | 1.0132 bar |
| 2 atm | 2.0265 bar |
| 3 atm | 3.0398 bar |
| 5 atm | 5.0663 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 | 253.3125 bar |
| 500 atm | 506.625 bar |
| 1,000 atm | 1,013.25 bar |
Frequently asked questions
How many bars are in a atmosphere? +
There are 1.01325 bars in one atmosphere.
What is 10 atm in bar? +
10 atm equals 10.1325 bar. Multiply 10 by 1.01325.
How do I convert bar back to atmosphere? +
Use atmosphere = bar ÷ 1.01325. The converter above handles both directions, or see our dedicated bar to atm page.
How accurate is this atmosphere to bar conversion? +
The factor used is 1.01325, carried at full double precision. Where a unit has an exact legal definition the factor is exact rather than approximate. Rounding is applied only to the displayed result, so the answer is never a calculation done on an already-rounded number.
Is there a quick way to estimate atm to bar in my head? +
Round the factor to 1.01 and multiply. That is 0.3208% off the exact value of 1.01325, which is fine for a rough figure and not for anything that has to balance.