This converter turns bar into atmospheres instantly, using the exact factor 1 bar = 0.9869232667 atmospheres. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
Almost exactly atmospheric pressure; standard in European industry and diving. Standard atmospheric pressure by definition — 101,325 pascals exactly.
Because the relationship is a simple proportion, one multiplication does the whole job. The table further down gives pre-computed values for the amounts people look up most often, and the result panel also reports the reverse conversion so you can check the figure both ways.
The formula
bar- The amount you are converting, measured in bar
0.9869232667- The exact number of atmospheres in one bar
atmospheres- The converted result
How it works, step by step
- Enter the number of bar you want to convert.
- The value is multiplied by 0.9869232667, the exact conversion factor.
- The result is displayed in atmospheres, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 bar
Multiply 5 by 0.98692327. That gives 4.9346 atmospheres. A quick sanity check: one bar is smaller than one atmosphere, so the number should get smaller — and it does.
Converting 72 bar
72 × 0.98692327 = 71.0585 atmospheres. Working backwards, 71.0585 ÷ 0.98692327 returns 72 bar, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many atmospheres are in one bar?
Exactly 0.9869232667. Every conversion on this page is that single number multiplied by your input, so the result carries no rounding error beyond what is shown.
What is the formula to convert bar to atmospheres?
Atmospheres = bar × 0.9869232667. To reverse it, divide instead: bar = atmospheres ÷ 0.9869232667, which is the same as multiplying by 1.01325.
Is the bar bigger than the atmosphere?
No. One bar is only 0.986923 of a atmosphere, so the atmosphere is the larger unit.
Why does my answer differ slightly from other bar to atmospheres converters?
Most differences come from rounding the factor too early. This tool keeps full double precision through the calculation and only rounds at the final display step, and it also shows the unrounded value so you can see exactly where any difference appears.
What is a bar?
Almost exactly atmospheric pressure; standard in European industry and diving.
What is a atmosphere?
Standard atmospheric pressure by definition — 101,325 pascals exactly.
Bar to atmospheres reference table
| Bar | Atmospheres |
|---|---|
| 0.5 bar | 0.493462 atm |
| 1 bar | 0.986923 atm |
| 2 bar | 1.9738 atm |
| 3 bar | 2.9608 atm |
| 5 bar | 4.9346 atm |
| 10 bar | 9.8692 atm |
| 15 bar | 14.8038 atm |
| 20 bar | 19.7385 atm |
| 25 bar | 24.6731 atm |
| 50 bar | 49.3462 atm |
| 75 bar | 74.0192 atm |
| 100 bar | 98.6923 atm |
| 250 bar | 246.7308 atm |
| 500 bar | 493.4616 atm |
| 1000 bar | 986.9233 atm |
Exact factor: 1 bar = 0.9869232667 atmospheres. Values rounded for display.