Pressure Converter

Divide PSI by 14.504 to get bar. For example, 32 PSI ÷ 14.504 = 2.2 bar. Alternatively, multiply PSI by 0.0689. This conversion is commonly needed when comparing US and European tire pressure recommendations.

Multiply bar by 14.504 to get PSI. For example, 2.0 bar × 14.504 = 29.0 PSI. For a quick estimate, multiply bar by 14.5. European tire pressure specs often use bar; US specs use PSI.

1 standard atmosphere (atm) = 101.325 kPa = 14.696 PSI = 1.01325 bar = 760 mmHg. This is the average air pressure at sea level. Weather reports show deviations from this standard, affecting weather patterns.

Blood pressure uses mmHg (millimeters of mercury) for historical reasons—early sphygmomanometers used mercury columns. Normal blood pressure is about 120/80 mmHg (systolic/diastolic). To convert: 1 mmHg = 0.133 kPa.

Check the sticker on your driver's door jamb or owner's manual—not the tire sidewall (that shows maximum). Typical passenger car: 30-35 PSI (2.0-2.4 bar). Check pressure when tires are cold. Underinflation wastes fuel; overinflation reduces grip.

Gauge pressure is relative to atmospheric pressure (what most gauges show). Absolute pressure includes atmospheric pressure. Absolute = Gauge + Atmospheric. A tire at 32 PSIg (gauge) is actually 32 + 14.7 = 46.7 PSIa (absolute).

Pascal (Pa) is the SI unit of pressure, equal to 1 Newton per square meter (N/m²). It's very small, so kilopascals (kPa) are common. 1 kPa = 1,000 Pa. Atmospheric pressure ≈ 101.3 kPa. Named after Blaise Pascal, mathematician.

Underwater pressure increases by 1 atm per 10 meters (33 feet). At 30m depth: 4 atm total (3 from water + 1 atmospheric). Dive tanks are filled to 200-300 bar (2,900-4,350 PSI). Decompression sickness ("the bends") relates to pressure changes.