Convert Atmospheres to Bars
Convert Atmospheres to Bars instantly. 1 Atmosphere (atm) equals 1.0133 Bars (bar).
Atmospheres to Bars conversion table
| Atmospheres (atm) | Bars (bar) |
|---|---|
| 1 atm | 1.0133 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 |
| 50 atm | 50.6625 bar |
| 100 atm | 101.325 bar |
| 500 atm | 506.625 bar |
| 1,000 atm | 1,013.25 bar |
1 Atmosphere = 1.0133 Bars · multiply Atmospheres by 1.0133
About converting Atmospheres to Bars
Atmospheres (atm) and Bars (bar) are both units of pressure, so converting between them is a single multiplication: multiply your Atmospheres figure by 1.0133. Ten Atmospheres comes to 10.1325 Bars, and a hundred works out at 101.325 Bars.
Rule of thumb: going from Atmospheres to Bars multiplies, so the figure always grows — one Atmosphere is already 1.0133 Bars. If your answer came out smaller, you have the conversion the wrong way round.
What is an Atmosphere?
The standard atmosphere is a defined reference rather than a working unit: a figure fixed by agreement at roughly what the air presses at sea level on an ordinary day. Nobody sets a gauge to it. Instead it is the yardstick other pressures are described against — divers count depth in atmospheres, chemists specify reactions at one atmosphere, and test standards quote pressures as multiples of it. Because it is a defined number rather than a measured one, the real pressure outside almost never equals exactly one atmosphere; it wanders with the weather, which is what a barometer is telling you.
What is a Bar?
The bar is not an SI unit, but it is accepted for use alongside them, and it earns that place by sheer convenience: it was chosen to sit close to average atmospheric pressure, so "one bar" reads as roughly what the air is doing right now. It dominates European industry — compressed air, hydraulics, scuba cylinders, espresso machines and tyre pressures are all quoted in bar. Its subdivision the millibar had a long career in weather forecasting before being quietly replaced by the hectopascal, which is exactly the same size, so nothing on the old charts had to change.
To put both in perspective: the pressure 10 metres underwater is about 2 atmospheres, while a scuba tank is filled to about 200 bar.
The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Bars to Atmospheres converter, or browse all Pressure converters.
Frequently asked questions
How many Bars are in one Atmosphere?
There are 1.0133 Bars in one Atmosphere.
How do I convert Atmospheres to Bars?
Multiply the number of Atmospheres by 1.0133. For example, 10 Atmospheres = 10.1325 Bars.
What is 100 Atmospheres in Bars?
100 Atmospheres is equal to 101.325 Bars.
How do I convert Bars to Atmospheres?
Multiply the Bars value by 0.9869 (or divide by 1.0133).
Is this Atmospheres to Bars conversion exact?
The definition is exact — Atmospheres and Bars are both fixed against the same base by international agreement — but the decimal shown here is rounded for readability, because the true ratio does not terminate. For engineering or scientific work, carry more decimal places than this page displays.
What is an Atmosphere?
The standard atmosphere is a defined reference rather than a working unit: a figure fixed by agreement at roughly what the air presses at sea level on an ordinary day. Nobody sets a gauge to it. Instead it is the yardstick other pressures are described against — divers count depth in atmospheres, chemists specify reactions at one atmosphere, and test standards quote pressures as multiples of it. Because it is a defined number rather than a measured one, the real pressure outside almost never equals exactly one atmosphere; it wanders with the weather, which is what a barometer is telling you.
What is a Bar?
The bar is not an SI unit, but it is accepted for use alongside them, and it earns that place by sheer convenience: it was chosen to sit close to average atmospheric pressure, so "one bar" reads as roughly what the air is doing right now. It dominates European industry — compressed air, hydraulics, scuba cylinders, espresso machines and tyre pressures are all quoted in bar. Its subdivision the millibar had a long career in weather forecasting before being quietly replaced by the hectopascal, which is exactly the same size, so nothing on the old charts had to change.