Convert bar to atm
Convert bar to atm instantly. 1 bar = 0.986923 atm. Formula, worked examples and a quick reference table.
Last updated
One bar equals 0.986923 atmospheres. To convert any number of bars to atmospheres, multiply by 0.98692327.
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.
bar to atm formula
To go the other way, use bar = atmosphere ÷ 0.98692327.
About these units
One bar is 100,000 pascals, very close to average atmospheric pressure at sea level — which is why it was chosen.
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.
Bar is also written bars. Atmosphere is also written atmospheres.
Sources
bar to atm conversion table
| Bar | Atmosphere |
|---|---|
| 1 bar | 0.9869 atm |
| 2 bar | 1.9738 atm |
| 3 bar | 2.9608 atm |
| 5 bar | 4.9346 atm |
| 10 bar | 9.8692 atm |
| 20 bar | 19.7385 atm |
| 25 bar | 24.6731 atm |
| 50 bar | 49.3462 atm |
| 100 bar | 98.6923 atm |
| 250 bar | 246.7308 atm |
| 500 bar | 493.4616 atm |
| 1,000 bar | 986.9233 atm |
Frequently asked questions
How many atmospheres are in a bar? +
There are 0.986923 atmospheres in one bar.
What is 10 bar in atm? +
10 bar equals 9.8692 atm. Multiply 10 by 0.98692327.
How do I convert atmosphere back to bar? +
Use bar = atmosphere ÷ 0.98692327. The converter above handles both directions, or see our dedicated atm to bar page.
How accurate is this bar to atmosphere conversion? +
The factor used is 0.9869232667, 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 bar to atm in my head? +
The factor is exactly 0.987, which is short enough to apply directly without an approximation.