When it comes to measuring pressure, there are various units used around the world. Two commonly used units are PSI (pounds per square inch) and bar. While PSI is predominantly used in the United States, bar is the preferred unit in many other countries. Understanding the conversion between these two units is essential for anyone working with pressure measurements. In this article, we will delve into the details of PSI to bar conversion, explore the differences between the two units, and provide practical examples to enhance your understanding.

The Basics: PSI and Bar

Before we dive into the conversion process, let’s take a moment to understand the basics of PSI and bar.

PSI (Pounds per Square Inch)

PSI is a unit of pressure commonly used in the United States. It measures the force exerted on an area of one square inch. Originally derived from the English system of measurement, PSI is widely used in various industries, including automotive, aviation, and manufacturing.


Bar, on the other hand, is a unit of pressure used in many countries around the world. It is derived from the metric system and measures pressure in multiples of atmospheric pressure. One bar is equivalent to 100,000 pascals (Pa), which is approximately equal to the average atmospheric pressure at sea level.

The Conversion: PSI to Bar

Converting PSI to bar involves a simple mathematical calculation. The conversion factor between the two units is 0.0689475729. To convert PSI to bar, you can multiply the PSI value by this conversion factor.

Let’s take an example to illustrate the conversion:


You have a pressure reading of 30 PSI. To convert it to bar, you can use the following formula:

Pressure in bar = Pressure in PSI × Conversion factor

Plugging in the values:

Pressure in bar = 30 PSI × 0.0689475729

Pressure in bar ≈ 2.0684 bar

Therefore, 30 PSI is approximately equal to 2.0684 bar.

Practical Applications

Understanding the conversion from PSI to bar is crucial in various industries and applications. Let’s explore some practical examples where this conversion is commonly used:

1. Automotive Industry

In the automotive industry, tire pressure is typically measured in PSI. However, many European car manufacturers provide recommended tire pressure in bar. Knowing how to convert PSI to bar allows car owners to accurately maintain the recommended tire pressure for optimal performance and safety.

2. Industrial Machinery

Industrial machinery often operates under specific pressure requirements. Engineers and technicians need to be able to convert pressure measurements between PSI and bar to ensure the machinery is operating within the desired parameters. This is crucial for maintaining efficiency, safety, and preventing equipment failure.

3. Scuba Diving

Scuba divers use pressure gauges to monitor the air pressure in their diving tanks. These gauges typically display pressure in bar. However, some divers may be more familiar with PSI. Understanding the conversion allows divers to interpret pressure readings accurately and make informed decisions during their dives.


Q1: Why are there different pressure measurement units?

A1: Different pressure measurement units exist due to historical reasons and regional preferences. The United States adopted PSI from the English system, while many other countries embraced the metric system and use bar as the standard unit for pressure measurement.

Q2: Can I use an online converter to convert PSI to bar?

A2: Yes, there are numerous online converters available that can quickly and accurately convert PSI to bar. However, it is always beneficial to understand the conversion process to ensure accuracy and have a deeper understanding of the measurements.

Q3: Are there any other commonly used pressure measurement units?

A3: Yes, there are several other pressure measurement units used in specific industries and applications. Some examples include pascal (Pa), kilopascal (kPa), and atmosphere (atm).

Q4: Is it possible to convert bar to PSI?

A4: Yes, the conversion from bar to PSI is also straightforward. You can use the conversion factor of 14.5038 to convert bar to PSI. Simply multiply the bar value by this conversion factor to obtain the equivalent PSI value.

Q5: Can I convert PSI to bar using a different conversion factor?

A5: While the conversion factor of 0.0689475729 is widely accepted, it is important to note that using a different conversion factor may result in slightly different values. It is recommended to use the standard conversion factor for accurate and consistent conversions.


Understanding the conversion from PSI to bar is essential for anyone working with pressure measurements. By converting PSI to bar, you can easily communicate and compare pressure values across different regions and industries. The conversion factor of 0.0689475729 allows for a straightforward calculation, ensuring accurate and consistent conversions. Whether you are in the automotive industry, working with industrial machinery, or engaging in scuba diving, knowing how to convert PSI to bar will enhance your ability to interpret and utilize pressure measurements effectively.