The exact equivalent
One bar is 14.5038 psi. A bar is defined as exactly 100,000 pascals, very close to one atmosphere at sea level.
1 bar = 14.50377377 psi
1 psi = 0.06894757 bar
How to convert it by hand
Just multiply by the conversion factor. To go from bars to pounds per square inch, multiply by 14.503774; to come back, divide by that same number or multiply by 0.068948.
For example: 25 bar × 14.503774 = 362.5943 psi.
A tip that saves mistakes: check the result goes the way you expect. If pounds per square inch are a smaller unit than bars, the number has to come out bigger. If it comes out smaller, you divided when you should have multiplied.
Conversion table
| bar | psi |
|---|---|
| 1 | 14.5038 |
| 2 | 29.0075 |
| 5 | 72.5189 |
| 10 | 145.0377 |
| 20 | 290.0755 |
| 50 | 725.1887 |
| 100 | 1,450.3774 |
Reference points to picture it
| Reference | Equals |
|---|---|
| A car tyre | 2.2 bar = 31.9 psi |
| A bicycle tyre | 6 bar = 87 psi |
| Atmospheric pressure | 1.013 bar = 14.7 psi |
| An espresso machine | 9 bar = 130.5 psi |
The trick for doing it in your head
Multiply by 14.5, or for a rough figure multiply by 15 and take a little off. For 2.2 bar: about 32 psi.
It is fine for getting by without a phone, but not for anything that depends on precision: in a recipe, on a building site or in a dose, use the exact conversion.