This all-in-one online Pressure Calculator performs calculations using a formula that relates the pressure exerted by a force on a certain surface area to the magnitude of this force and the size of the area. You can enter the values of any two known parameters in the input fields of this calculator and find the missing parameter.
What is Pressure
Pressure is a physical quantity representing a force applied perpendicularly to the surface of an object and distributed over a unit area of that object.
The mathematical formula for pressure is as follows:
$$P = \frac{F}{A},$$
where
\(P \,\) is the pressure,
\(F \,\) is the magnitude of the normal force,
\(A \,\) is the area of the surface to which the force is applied.
Pressure is a scalar quantity with dimension M·L-1·T−2. The SI unit of pressure is the pascal (Pa), which is equal to one newton per square meter (N/m2, or kg·m-1·s-2).
In addition to pascal, its derivatives are also used:
1 hectopascal (hPa) = 100 Pa,
1 kilopascal (kPa) = 1000 Pa,
1 megapascal (MPa) = 106 Pa,
1 gigapascal (GPa) = 109 Pa.
Other commonly used pressure units are also included in our Pressure calculator.
The bar is a metric unit of pressure, but not a SI unit. It is defined as exactly equal to 100,000 Pa (100 kPa), or slightly less than the current average atmospheric pressure on Earth at sea level (approximately 1.013 bar).
The pound per square inch (psi) or, more accurately, pound-force per square inch is the pressure resulting from a force of 1 pound-force applied to an area of 1 square inch. In SI units, 1 psi is approximately equal to 6894.76 Pa.
The technical atmosphere (at) is the pressure resulting from a force of 1 kilogram-force applied to an area of 1 square centimeter and is equal to 98066.5 Pa.
The standard atmosphere (atm) is an established constant. It is approximately equal to typical air pressure at Earth mean sea level and is defined as 101325 Pa.
The Torr is defined as 1/760 of the standard atmosphere: 1 atm = 760 Torr. So 1 Torr is approximately equal to 133.32 Pa.
Manometric units such as the millimeter of mercury, and inch of mercury are often used to express pressures in terms of the height of column of fluid mercury in a manometer.
The inch of mercury (inHg): 1 inHg = 3386.38 Pa,
The millimeter of mercury (mmHg): 1 mmHg = 133.322 Pa.
Since a system under pressure can do work on objects outside of this system, pressure is also a measure of the potential energy contained in a unit volume. It is therefore related to energy density and may be expressed in units such as joules per cubic meter (J/m3, which is equal to Pa).
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Check out our other physics calculators such as Kinetic Energy Calculator or Momentum Calculator .