PSI Conversion
Convert pounds per square inch (PSI) to bar, atm, Pa, kPa, MPa, mmHg, inHg, and torr instantly with this free pressure converter. Includes comparison chart and breakdown table for all pressure units.
About This Calculator
The PSI Conversion Calculator is a free online tool that converts pounds per square inch (PSI) into eight different pressure units: bar, atmospheres (atm), pascals (Pa), kilopascals (kPa), megapascals (MPa), millimeters of mercury (mmHg), inches of mercury (inHg), and torr. This converter is ideal for engineers, mechanics, divers, HVAC technicians, and anyone working with pressure measurements across different unit systems.
The conversion uses the standard formula: 1 PSI = 6894.76 pascals. To convert PSI to any other unit, the calculator first converts PSI to pascals (the SI base unit for pressure), then divides by the pascal equivalent of the target unit. For example, 1 bar = 100,000 Pa, so PSI to bar multiplies PSI by 0.0689476. The calculator provides instant results for all units simultaneously along with a comparison chart and breakdown table for easy reference.
Regional Notes
India: While India uses the metric system (kPa, bar) for most official pressure measurements, PSI is still encountered in imported equipment, automotive tire gauges from the US, and some industrial machinery. A typical car tire pressure in India is 30-35 PSI or 2.1-2.4 bar.
United States: PSI is the primary pressure unit used in the US for tire pressure, fuel systems, hydraulic systems, and HVAC. Understanding PSI conversions is essential when working with equipment from metric-using countries or international standards.
United Kingdom: The UK uses a mix of bar and PSI. Tire pressures are commonly given in both PSI and bar on vehicle placards. Scuba tanks in the UK often use bar (typically 200-300 bar), while some industrial gauges display PSI.
Frequently Asked Questions
What is PSI and how is it used?
PSI stands for pounds per square inch, a unit of pressure that measures the force applied over one square inch of area. It is widely used in the United States for tire pressure, scuba tanks, hydraulic systems, and industrial pressure gauges. One PSI equals the pressure exerted by one pound of force on one square inch.
How do you convert PSI to bar?
To convert PSI to bar, multiply the PSI value by 0.0689476. For example, 100 PSI × 0.0689476 = 6.89476 bar. Conversely, to convert bar to PSI, divide the bar value by 0.0689476. Our calculator handles this conversion instantly for any value.
How do you convert PSI to atmospheres (atm)?
To convert PSI to atm, divide the PSI value by 14.696. For instance, 29.39 PSI ÷ 14.696 = 2 atm. The reverse conversion multiplies atm by 14.696 to get PSI. Standard atmospheric pressure at sea level is 14.696 PSI or 1 atm.
How do you convert PSI to pascals (Pa)?
To convert PSI to pascals, multiply the PSI value by 6894.76. For example, 30 PSI × 6894.76 = 206,842.8 Pa. To convert from pascals to PSI, divide by 6894.76. Pascal is the SI unit of pressure, so this conversion is common in scientific and engineering contexts worldwide.
Is this PSI conversion calculator free to use?
Yes, this PSI converter is completely free to use with no registration or downloads required. You can convert PSI to bar, atm, Pa, kPa, MPa, mmHg, inHg, and torr instantly. The tool includes a comparison chart and breakdown table for all pressure units.
What is the difference between PSI and PSIG?
PSI (pounds per square inch) measures absolute pressure, while PSIG (pounds per square inch gauge) measures pressure relative to atmospheric pressure. PSIG = PSI - 14.696 (at sea level). For example, 30 PSIG equals approximately 44.696 PSI absolute. Our pressure converter focuses on absolute PSI conversions.
Can pressure be negative?
In absolute terms, pressure cannot be negative as it represents force exerted over an area. However, relative negative pressure can exist, indicating a pressure lower than the surrounding atmospheric pressure. This is also called partial vacuum or gauge vacuum.
What are common applications of PSI conversion?
PSI conversion is essential in automotive tire pressure (typically 30-35 PSI for cars), scuba diving (tanks filled to 3000 PSI), hydraulic systems, pneumatic tools, HVAC refrigerant pressures, water pressure systems, and industrial manufacturing where different pressure units are used across regions and equipment.