Convert Pound per Square Inch to Bar (psi → bar)

Converting psi to bars is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in psi

   Start with the number of psi (psi) you want to convert.
2. 2
   Multiply by 0.068948

   The conversion factor from psi to bar is 0.068948. Multiply your value by this number.
3. 3
   Read the result in bars

   The result is your value in bars (bar).

Multiply the value in psi by 0.068948. For the reverse direction, multiply by 14.503774.

• ✓1 psi ≈ 6.9 kPa = 0.069 bar.
• ✓14.7 psi = 1 atm = 1.01 bar.
• ✓Most US pressure gauges show psi.

• ✗Setting a European tyre at 35 bar instead of 35 psi — disaster.
• ✗Confusing psi (gauge) with psia (absolute).
• ✗Using psi in scientific papers — prefer Pa or MPa.

What is the Pound per Square Inch?

Pounds per square inch (psi) equals approximately 6,895 pascals and is the standard pressure unit in American tire pressures, hydraulics, and gas-cylinder specifications. American car tires are typically inflated to 30–35 psi, household water systems run at 40–60 psi, and scuba tanks are filled to 3,000 psi (about 200 bar). The psi is essential in American engineering for stress calculations, hydraulic systems, and pneumatic equipment. Two variants exist: 'psig' (gauge, measured above atmospheric) and 'psia' (absolute, including atmosphere) — gauge is the default unless specified. The psi relates to the pascal (1 psi ≈ 6,895 Pa), the kilopascal (1 psi ≈ 6.895 kPa), the bar (14.504 psi = 1 bar), the atmosphere (14.696 psi = 1 atm), and the inch of mercury (1 inHg ≈ 0.491 psi). Outside the US, kPa or bar dominate.

• US tyre pressures
• US plumbing and water system specs
• US compressed-air tool ratings

What is the Bar?

The bar equals exactly 100,000 pascals (100 kPa) and is the everyday pressure unit in European tire pressures, hydraulic systems, and meteorology. The unit was chosen to be approximately equal to atmospheric pressure at sea level (1 bar = 0.987 atm). European cars have tire pressures of about 2.0–2.5 bar (29–36 psi), industrial hydraulic systems operate at 100–700 bar, and wine bottles are pressurized to about 6 bar internally for sparkling wines. Although technically not an SI unit, the bar is widely accepted for use with the SI system. Weather forecasts in some countries use 'millibar' (1 mbar = 1 hPa = 100 Pa) for atmospheric pressure. The bar relates to the pascal (100,000 Pa = 1 bar), the kilopascal (100 kPa = 1 bar), the psi (1 bar ≈ 14.504 psi), the atmosphere (1 atm ≈ 1.013 bar), and the mbar (1,000 mbar = 1 bar). It strikes a practical balance between scientific precision and everyday usefulness.

• European tyre pressure gauges
• Scuba-diving depth pressure
• Hydraulic and pneumatic systems