Pressure is the force applied perpendicular to the surface of an object per unit area. It's a fundamental measurement in physics, engineering, meteorology, medicine, and many other fields. Understanding pressure conversions is essential for working with gases, liquids, weather systems, medical equipment, and industrial processes.
Pressure is measured in various units depending on the application and region. The SI unit is the pascal (Pa), but many other units are commonly used, including bar, psi (pounds per square inch), atmosphere (atm), and torr. Each unit has specific applications and conversion factors.
Pascal (Pa): The SI unit of pressure. One pascal equals one newton per square meter. For practical applications, kilopascals (kPa) and megapascals (MPa) are more commonly used. Standard atmospheric pressure is approximately 101,325 Pa or 101.325 kPa.
Bar: Widely used in Europe and meteorology. One bar equals 100,000 pascals, which is very close to standard atmospheric pressure (1 bar ≈ 0.987 atm). The bar is convenient because it's close to atmospheric pressure, making it easy to work with.
PSI (Pounds per Square Inch): Common in the United States for tire pressure, industrial applications, and engineering. One psi equals approximately 6.895 kPa or 0.0689 bar. Tire pressures are typically measured in psi in the US.
Atmosphere (atm): Based on standard atmospheric pressure at sea level. One atmosphere equals 101,325 Pa, 1.01325 bar, or 14.696 psi. This unit is useful for understanding pressure relative to Earth's atmosphere.
Pascal/Bar: Use in scientific work, European engineering, and meteorology. Bar is particularly common in weather reporting and industrial processes in Europe.
PSI: Essential for US automotive (tire pressure), industrial applications, and engineering specifications. Most US vehicles specify tire pressure in psi.
Atmosphere: Useful for understanding pressure relative to sea level, scuba diving, and atmospheric science. Divers use atmospheres to understand pressure at depth.
Torr/Millimeter of Mercury (mmHg): Used in medicine for blood pressure measurements and in vacuum technology. Blood pressure is typically measured in mmHg.
For quick mental conversions, remember: 1 bar ≈ 14.5 psi, 1 atm ≈ 14.7 psi, and 1 psi ≈ 6.9 kPa. Standard atmospheric pressure is approximately 1 bar, 1 atm, 14.7 psi, or 101.3 kPa. Understanding these relationships helps with quick conversions.
When working with tire pressure, note that European vehicles typically specify pressure in bar, while American vehicles use psi. Always check your vehicle's specifications and use the correct unit to avoid over or under-inflation.
Convert between psi, bar, pascal, and other pressure units. Use the formulas and examples below for quick reference.
To convert psi (pounds per square inch) to bar, multiply psi by 0.0689476.
bar = psi × 0.0689476
Example: 100 psi × 0.0689476 = 6.89476 bar
To convert bar to psi, multiply bar by 14.5038.
psi = bar × 14.5038
Example: 2 bar × 14.5038 = 29.0076 psi
Weather forecasting
Systems design and fluid dynamics
Blood pressure monitoring
Tire pressure maintenance
Altimeter settings
Processes and manufacturing
Calculating safe depths
How do you convert psi to bar?
Multiply psi by 0.0689476. For example, 100 psi × 0.0689476 = 6.89476 bar.
What is the formula for bar to psi?
Multiply bar by 14.5038. For example, 2 bar × 14.5038 = 29.0076 psi.
How many bar is 1 psi?
1 psi = 0.0689476 bar.
Pressure is the force applied perpendicular to the surface of an object per unit area. The SI unit for pressure is the pascal (Pa), which is equivalent to one newton per square meter (N/m²).
The standard SI unit of pressure, defined as one newton per square meter.
Equal to 1,000 pascals, commonly used in meteorology and engineering.
Approximately equal to atmospheric pressure at sea level, and equal to 100,000 pascals.
The average pressure at sea level, equal to 101,325 pascals.
Commonly used in the US and UK, especially for tire pressure.
The pressure exerted by a column of mercury 1 millimeter high, commonly used in medical and meteorological applications.
Used in weather reports and aviation altimeters in the United States.
Named after Evangelista Torricelli, approximately equal to 1 mmHg, used in vacuum measurements.
