Change the unit, keep the convention
One bar is exactly 100,000 pascals; one PSI is 6,894.757293168 pascals. Multiply bar by 14.5037737730 to obtain PSI, or multiply PSI by 0.06894757293168 to obtain bar. Calculations use the unrounded constants.
Gauge pressure is relative to the surrounding atmosphere; absolute pressure is relative to a vacuum. A bar(g) reading converts to PSI gauge. A bar(a) reading converts to PSI absolute. Converting between those conventions requires atmospheric pressure and is outside this tool. Nonnegative readings are supported here.
Bar and PSI conversion table
| bar | PSI |
|---|---|
| 1 | 14.5038 |
| 6 | 87.0226 |
| 7 | 101.526 |
| 8 | 116.030 |
| 10 | 145.038 |
Worked example: 7 bar gauge
7 × 100,000 ÷ 6,894.757293168 = approximately 101.526 PSI gauge. In reverse, 100 PSI gauge is 6.894757293168 bar gauge. Neither calculation changes gauge pressure to absolute pressure.
Put the pressure at the point of use in your brief
Record the working pressure required by the tools and where it is measured. Supply airflow separately, with its reference conditions. Allow for the actual pipe and treatment arrangement when discussing the compressor pressure; a converted figure alone does not select equipment. Use the pipe calculator for a simple pipe-run estimate.