Bar and pounds per square inch
One bar equals 14.5037738 pounds per square inch, usually written psi. Pressure is force distributed over an area, so it is not interchangeable with force, energy, or a tyre's load. The factor converts the reading's unit while leaving the physical pressure represented by the gauge unchanged.
A compressor setting
Ten bar converts to 145.04 psi. A workshop regulator marked 6.5 bar is about 94.27 psi, but the pressure at a tool can be lower because of hose length, fittings, flow, and a clogged filter. Use the equipment's specified operating range rather than selecting a setting from conversion alone.
Gauge pressure is not always absolute
Many gauges report pressure above local atmospheric pressure, whereas scientific and refrigeration specifications may use absolute pressure. Adding or omitting atmospheric pressure changes the reference, not merely the unit. A value labelled barg should not be treated as bara without knowing the system convention.
Where specialist data is required
This converter changes bar to psi only. It does not set tyre pressure, size a pressure vessel, calculate gas volume, or approve a hydraulic system. Follow the placard, manufacturer manual, and safety procedure for pressurised equipment.
Temperature can change the reading
A sealed gas system can show a different pressure after warming even when no gas has been added. Tyre and compressor instructions often specify whether the reading should be cold, running, or stabilized. Converting 2.4 bar to 34.81 psi preserves the measurement, but it does not make a hot reading comparable with a cold placard. Record the condition alongside the number whenever a pressure trend is being checked.
Check the expected size
Psi is a smaller pressure unit than bar, so the psi number is larger. One bar is about 14.5 psi, making a 10 bar reading near 145 psi. A result around 1.45 psi signals a misplaced decimal. This numerical check does not establish which reference pressure the gauge used, but it does test the unit arithmetic.
Release pressure safely
Never use a converted gauge value as permission to alter a sealed system. Isolation, rated fittings, and the specified depressurising procedure are safety requirements outside this arithmetic. A gauge that is damaged, disconnected, or beyond its calibration date needs correction before its unit label has any operational value.