Table of contents
Pounds per square inch
The pounds per square inch [psi] is a unit of pressure and stress according to the Imperial and US customary systems of units. The unit is derived from the pound-force lb-f, a unit of force and the inch squared, which is a unit of area. The psi unit describes how many pounds (force) are applied on a unit area of square inch. The definition of psi depends on the definitions of the pound-force and the inch units.
Pound-force [lb-f] is defined as the force of gravity on the earth's surface upon a mass equal to one avoirdupois pound. Its equivalence to the respective metric unit, the Newton [N] is: 1 lb-f = 4.4482216152605 N. The above definition depends on the earth's gravity g, which varies from place to place, but is typically standardized as g ≈ 9.80665 m/s2 ≈ 32.174049 ft/s2.
Inch [in] is a unit of length for the Imperial and US customary system of units. It was historically conceived as the length of 3 barley-corns. Today, it is defined through the meter [m] SI unit as: 1 in = 0.0254 m (= 2.54 cm = 25.4 mm).
With the above definitions of lb-f and the inch, relative to their metric equivalents, the conversion rule from psi to KPa becomes:
The relationship between psi and other units of pressure and stress are shown in the following table:
Kilopascal [KPa] is a unit of pressure and stress according to the SI system of units. It is a multiple of Pascal [Pa] (1 KPa = 1000 Pa), which is a derived unit, based on the Newton [N], a unit of force and the meter squared, which is a unit of area. The Pa unit describes how many Newtons (force) are applied on a unit area of square meters.
The relationship between KPa and other units of pressure and stress are shown in the following table:
|Gigapascal||GPa||1 000 000|
|Pounds per sq. inch||psi||6.89476|
How to convert pounds per sq. inch to kilopascal (psi to KPa)
- Multiply pressure/stress in psi with 6.89476
- The result is the pressure/stress in KPa
For example 10psi is 10x6.89476 ≈ 68.95 KPa
How to convert kilopascal to pounds per sq. inch (KPa to psi)
- Divide pressure/stress in KPa by 6.89476
- The result is the pressure/stress in psi
For example 100 KPa is 100/6.89476 ≈ 14.50 lb
Conversion table from KPa to psi
In the following table some typical pressures in KPa are converted to psi:
Conversion table from psi to KPa
In the following table some typical pressures in psi are converted to KPa: