Multiply pressure in bar by 14.5038
The bar-to-PSI conversion factor (14.5038) derives from the pascal as the common base. 1 bar = 100,000 Pa; 1 PSI = 6,894.76 Pa, the force of one pound across one square inch (4.448 newtons across 6.4516 cm²). Dividing gives 14.5038 PSI per bar. The conversion is exact and linear — no temperature or fluid-density correction needed, because bar and PSI both measure absolute force per area, not gauge or differential pressure.
Bar and PSI both measure pressure but come from different traditions. The bar is a metric unit defined as exactly 100,000 pascals, roughly equal to atmospheric pressure at sea level. PSI (pounds per square inch) is the imperial unit dominant in the United States, used everywhere from tire gauges to hydraulic equipment.
One bar equals 14.5038 PSI. The two units coexist in everyday life: European car manuals quote tire pressures in bar, American gas station gauges read PSI, and most modern dual-scale gauges show both.
Bar-to-PSI conversion comes up constantly when reading mixed-region equipment manuals, ordering parts from foreign suppliers, or following service guides written for another market.
European cars list recommended tire pressure in bar (2.2-2.5 typical). US gas-station gauges read PSI. Quick conversion avoids over- or under-inflation when traveling or driving an import.
Aluminum 80 tanks rate 3000 PSI / 207 bar service pressure. Reading the wrong scale on a foreign-rented tank can lead to dangerous miscalculation of remaining air time.
Commercial espresso machines target 9 bar extraction pressure (~130 PSI). Home machines sometimes list PSI specs only. Calibrating an OPV (over-pressure valve) requires converting between the two.
European industrial hydraulics rate in bar; American spec sheets in PSI. Service manuals translated from one market to another frequently mix units within a single page.
Pneumatic tool requirements list PSI (90 PSI is the US woodworking standard); compressor regulators sold in EU markets often display bar. Convert to confirm the compressor can deliver tool spec.
Multiply the bar value by 14.5038. So 2 bar = 29.0 PSI, 5 bar = 72.5 PSI, 10 bar = 145.0 PSI. The conversion is exact and works for any positive value.
1 bar equals 14.5038 PSI, usually rounded to 14.5 PSI in everyday use. The exact value comes from the SI definition of bar as 100,000 pascals.
Most passenger cars run 2.0-2.5 bar (29-36 PSI) cold. Check the door-jamb sticker or owner's manual for the manufacturer's spec — it varies by tire size, load, and front vs rear axle.
By convention, both bar and PSI in everyday equipment specs refer to gauge pressure — pressure above atmospheric. When absolute pressure matters (vacuum systems, aerospace), the unit is written as 'bara' (bar absolute) or 'PSIA' to remove ambiguity.
1 bar = 0.987 atmospheres, almost equal but not identical. One atmosphere is defined as exactly 101,325 pascals, while one bar is exactly 100,000 pascals. The 1.3% difference rarely matters outside scientific contexts.
Bar is part of the metric system used across Europe for industrial and automotive pressure measurement. PSI is rare on European spec sheets except where they explicitly target US export markets.
For tire pressure, espresso machines, and most everyday uses, 14.5 is accurate enough. Use the full 14.5038 for engineering calculations or whenever precision matters past one decimal.
Kilopascals (kPa) are the SI unit some modern car manuals use. 1 bar = 100 kPa = 14.5038 PSI. Three units, one underlying physical quantity — pick whichever your gauge displays.