Pounds per Square Inch to Bar

Pounds per square inch and bar

One psi is the pressure of one pound-force on one square inch: about 6,894.757 pascals, derived from exact definitions. Tire pressure in the US and UK, air compressors, pressure washers and plumbing use psi.

The bar is exactly 100,000 pascals, slightly less than one standard atmosphere. Tire pressure in Europe, espresso machines, scuba tanks and industrial gauges use bar.

Worked example

Convert 32 psi: 32 × 0.06894757293 = 2.206322334, so 32 pounds per square inch is 2.206322334 bar. Likewise 20 psi = 1.378951459 bar.

Estimating in your head

Divide by 15 for a quick figure; it is off by about 3.4%. For 32 psi that gives 2.13 bar, against 2.20632 exactly.

Going the other way

To convert bar to pounds per square inch, divide by 0.06894757293 (or multiply by 14.503773773). The swap button between the boxes opens that page.

bar = psi × 0.06894757293

1 psi = ≈ 6,894.757293 Pa and 1 bar = 100,000 Pa, both by definition, so the factor is their ratio: 0.06894757293 (rounded here; the page uses the full value). Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.