Bar to PSI Converter
Convert from Bar to Pounds per Square Inch (PSI)
Understanding Bar and PSI
The bar is a metric unit of pressure that is not part of the SI but is accepted for use with it.
- 1 bar = 100,000 pascals (Pa) = 100 kPa
- Approximately equal to atmospheric pressure at sea level
- Commonly used in meteorology and many engineering applications
PSI (pound-force per square inch) is a unit of pressure in the imperial and US customary systems.
- Commonly used in the United States and the UK
- Standard atmospheric pressure is approximately 14.7 PSI
- Widely used for tire pressure, hydraulic systems, and many industrial applications
Conversion Formula
Bar to PSI:
PSI = bar × 14.5038
To convert from bar to PSI, multiply the bar value by approximately 14.5038.
PSI to Bar:
bar = PSI × 0.0689476
To convert from PSI to bar, multiply the PSI value by approximately 0.0689476.
Bar to PSI Conversion Table
| Bar | Pounds per Square Inch (PSI) |
|---|---|
| 0.5 | 7.25 |
| 1 | 14.50 |
| 1.5 | 21.76 |
| 2 | 29.01 |
| 2.5 | 36.26 |
| 3 | 43.51 |
| 3.5 | 50.76 |
| 4 | 58.02 |
| 4.5 | 65.27 |
| 5 | 72.52 |
Historical Context and Applications
Historical Development
The bar unit was introduced in 1909 by Norwegian meteorologist Vilhelm Bjerknes and was designed to be close to atmospheric pressure at sea level. PSI has been used since the early days of steam power in the 18th century. Today, these two units represent the divide between metric and imperial measurement systems, with bar being more common in countries using the metric system and PSI predominant in the United States and some other English-speaking countries.
Common Applications
- Bar: Commonly used in Europe and most of the world for tire pressure, industrial equipment, and hydraulic systems. The bar is also frequently used in meteorology.
- PSI: Predominantly used in the United States for tire pressure, plumbing systems, and industrial applications. Most pressure gauges in the US are calibrated in PSI.
Practical Examples
- Standard atmospheric pressure: 1.01325 bar (14.7 PSI)
- Car tire pressure: 2.0-2.5 bar (29-36 PSI)
- Bicycle tire pressure: 4-8 bar (58-116 PSI)
- Espresso machine pressure: 9 bar (130.5 PSI)
- Home water pressure: 3-4 bar (43.5-58 PSI)
- Enter your value in the bar field
- The converter instantly displays the equivalent in PSI
- Use the swap button to convert from PSI to bar instead
- Results are displayed with 6 decimal places for precision
For quick reference without calculations, refer to the conversion table above for common values.