Convert atmospheres to bar
Converting atmospheres to bar is a common pressure task, whether you are checking a recipe, a spec sheet, a travel distance or a homework problem. Since 1 atm equals 1.01325 bar, the math is a single multiplication — and this page does it for you instantly, with the formula, a table of common values and answers to the questions people ask most.
Exact factor
How to convert atmospheres to bar
To convert atmospheres to bar, multiply the number of atmospheres by 1.01325. For example, 10 atm × 1.01325 = 10.1325 bar.
bar = atm × 1.01325
- Write down the value in atmospheres you want to convert.
- Multiply it by 1.01325 (the exact atm→bar factor).
- The result is your value in bar. Check it below with the converter or the table.
Conversion table
Common values of atmospheres and their equivalents in bar:
| atm | bar |
|---|---|
| 1 | 1.01325 |
| 2 | 2.0265 |
| 3 | 3.03975 |
| 4 | 4.053 |
| 5 | 5.06625 |
| 10 | 10.1325 |
| 20 | 20.265 |
| 25 | 25.3313 |
| 50 | 50.6625 |
| 100 | 101.325 |
| 250 | 253.313 |
| 500 | 506.625 |
About these units
Atmosphere (atm). One standard atmosphere is defined as exactly 101,325 pascals, the reference average pressure of Earth's atmosphere at sea level. It anchors chemistry and gas-law calculations.
Bar (bar). A bar equals exactly 100,000 pascals, close to average atmospheric pressure at sea level. It is the standard unit for tire pressure, dive tanks and espresso machines in metric countries.
Frequently asked questions
How do I convert atmospheres to bar?
To convert atmospheres to bar, multiply the number of atmospheres by 1.01325. For example, 10 atm × 1.01325 = 10.1325 bar. Or skip the math: type the value into the converter at the top of this page and the result updates instantly.
How many bar are in 1 atmosphere?
1 atm = 1.01325 bar. That is the fixed relationship used by this converter and by international standards.
How many atmospheres are in 1 bar?
1 bar = 0.986923 atm. If you are converting in the opposite direction, use our Bar to Atmosphere converter for the dedicated table and FAQ.
Is the atmospheres to bar conversion exact?
Yes. Both units are defined by international agreement, so the factor of 1.01325 is exact. Displayed results are rounded to 6 significant digits only for readability.
What is atmosphere used for?
One standard atmosphere is defined as exactly 101,325 pascals, the reference average pressure of Earth's atmosphere at sea level. It anchors chemistry and gas-law calculations.