Convert Psi to Bar

Imperial/US Customary unit of pressure. 1 psi is actually the pressure generated by applying 1 pound of force to an area of 1 square inch. Dominant in North America.

Critical for system design, safety, and matching air compressor output to application needs. Must know if working with equipment or standards from regions using imperial units.

As a commonly used unit of pressure measurement that can be provided or required by equipment and pipelines, pressure psi can be converted to bar. Usually, one of the parameters may be used to calculate the other, but using a complex parameter correspondence table will delay time, so it is more convenient to use pressure psi to convert bar and other units of conversion tools.

Metric unit of pressure. 1 bar is approximately equal to atmospheric pressure at sea level. Widely used globally (especially outside North America).

Crucial for specifying:

Working Pressure: The rated output pressure at which the air compressor is designed (e.g. 7 bar, 10 bar, 13 bar).

Maximum Working Pressure (MWP): The upper limit of the safe working pressure of the components of the storage and transfer system (tanks, pipes, hoses).

Tool/Equipment Requirements: Ensures the air compressor can provide sufficient pressure for air tools or processes.

Convert psi to bar: 1 bar ≈ 14.5 psi (Crucial for comparing specs or using equipment from different regions).

Compared to using a parameter table, Elang’s unit conversion tool is more convenient and quick to get the answer when converting pressure psi to bar.

A unit of volumetric flow. Imperial/U.S. customary units measuring the volume of air delivered by a air compressor per minute, which can usually be referenced to standard atmospheric conditions (e.g., 14.5 psia, 68°F, 0% RH).

KEY DIFFERENCE: FAD cfm (Free Air Delivery) is the actual useful flow rate delivered by the compressor at rated pressure.

Metric unit of volume flow. Mainly used to measure the volume of air delivered per minute under standard conditions (e.g. 1 bar(a), 20°C, 0% RH).

Conversion: 1 m³/min ≈ 35.3 cfm

Pressure (bar/psi): Dictates whether the air compressor can overcome the resistance in your system and power your tools/processes. Exceeding MWP is dangerous.

Flow Rate (FAD cfm / FAD m³/min): Determines if the air compressor can supply the volume of air needed to keep all tools/processes running simultaneously without excessive pressure drop. Undersizing causes operational problems.

Power (kW): Directly determines your electricity consumption and operating costs. The most accurate unit for comparing energy efficiency and calculating TCO (Total Cost of Ownership). Be skeptical of hp ratings.

FAD is King: For flow rate, ALWAYS use or specify Free Air Delivery (FAD) measured according to ISO 1217 (or equivalent like CAGI/Pneurop). This is the only meaningful flow rate figure for sizing your system. Disregard theoretical, displaced, or inlet CFM/m³/min for sizing purposes.

Standards Matter: ISO 1217 is the internationally recognized standard for testing and declaring air compressor performance (flow rate, power consumption, specific power). Adherence ensures accurate, comparable specifications between manufacturers. Safety standards (ISO 5390, EN 1012, ASME B19.3) are critical for system design and operation.

Need enough bar/psi to push the air through the system and run your tools.

Need enough FAD cfm / FAD m³/min to actually supply the volume of air those tools consume at that pressure.

Need to know the kW to understand how much it will cost to run.

hp is less reliable; focus on kW.

ISO 1217 FAD is the only flow rate figure you should trust for sizing.