Pressure conversion factor from psi to psf

Analyzing psi and psf Units

In this article, we'll explore pressure units and calculate the conversion factor from psi to psf.

• psi stands for pound-force per square inch, and is a common US unit for pressure. It's often informally referred to as pounds per square inch, although not entirely accurate.
• psf stands for pound-force per square foot, and is a common US unit for pressure. It's often informally referred to as pounds per square foot, although not entirely accurate.

As we delve into converting pressure units, we'll see that pressure relies on three fundamental quantities: mass, length, and time:

Pressure = force / area
         = mass · acceleration / area
         = mass · speed / time / area
         = mass · length / time² / length²
         = mass / time² / length

Given that both units are US units, and the only difference is the spread area, we'll only need the equivalence between ft and in to find the conversion factor.

How to Convert Pressure psi to psf

The equivalence between inches and feet:

ft = 12 in
in = 1/12 ft

Starting with the definition of pressure (force / area), we can convert ft units to in:

psf = lbf / ft²
    = lbf / (ft)²
    = lbf / (12 in)²
    = lbf / (144 in²)
    = 1/144 lbf / in²
    = 1/144 psi
    ≈ 0.006944444444444444 psi

Now, we can divide both sides of the equation by 1/144 psi:

psf / (1/144 psi) = 1

This manipulation provides us with the left side of the equation as a convenient conversion factor.

factor = psf / (1/144 psi)
       = 144 psf / psi

Applying this conversion factor to a pressure in psi, psi units cancel out, and we're left with the unit we're aiming for: psf.

Convert 10 psi to psf

Here's an example of how to convert a pressure of 10 psi into psf:

10 psi · factor
= 10 psi · 144 psf / psi
= 10 · 144 psf
= 1440 psf

psi to psf Conversion Factor

Here're the resulting key takeaways.

1 psf ≈ 0.006944444444444444 psi

Converting a psi unit into psf is as simple as multiplying it by a conversion factor:

psf = psi · factor

where factor is exactly:

factor = 144

Explore More

Here are some additional resources to deepen into this topic:

• Convert Pressure Units with this Converter.
• Check out other worked examples of how pressure conversion factors can be derived: psf to psi, MPa to psi, psi to MPa, or psi to ksi.
• Check out other worked examples of how force conversion factors can be derived: N to lbf, lbf to N, kN to lbf, or lbf to kN.