# psf - Pounds per Square Foot Pressure Unit

Pounds or Pounds Force per Square Foot is a British (Imperial) and American pressure unit which is directly related to the psi pressure unit by a factor of 144 (1 sq ft = 12 in x 12 in = 144 sq in). 1 Pound per Square Foot equals 47.8803 Pascals.

The psf pressure unit is mostly for lower pressure applications such as specifying building structures to withstand a certain wind force or rating a building floor for maximum weight load.

Use the list of pressure unit factors below to convert 1 pfsf into another engineering unit.

For reverse unit factors to convert into pfsf please click on the appropriate unit below.

Convert from or into Pounds (Force) per Square Foot using our pressure unit converter.

See the for how psf is deduced from SI units and check alternative ways of describing psf.

psf Pressure Conversion Factors

 0.000478803 bar 0.00694444 psi 0.478803 mbar 47.8803 N/m² 47.8803 Pa 0.478803 hPa 0.0478803 kPa 4.78803e-05 MPa 0.000488243 kg/cm² 4.88243 mmH2O 4°C (39.2°F) 0.488243 cmH2O 4°C (39.2°F) 0.00488243 mH2O 4°C (39.2°F) 0.192222 inH2O 4°C (39.2°F) 0.0160185 ftH2O 4°C (39.2°F) 0.359131 mmHg 0°C (32°F) 0.0359131 cmHg 0°C (32°F) 0.014139 inHg 0°C (32°F) 0.359131 Torr 359.131 mTorr 0.000472541 atm 0.000488243 at 478.803 dyn/cm² 0.111111 oz/in² 359.131 µHg 0°C (32°F) 3.1002e-06 tsi (uk, long) 3.47222e-06 tsi (usa, short) 0.0005 tsf (usa, short) 1 psf 0.488243 g/cm²

Please note that the conversion factors above are accurate to 6 significant figures.

psf Derivation
The calculation below shows how the pressure unit pounds per Square Foot (psf) is derived from SI Units.

Formula

Pressure = Force / Area
Force = Mass x Acceleration
Acceleration = Distance / (Second x Second)

SI Units

Mass: Kilogram (kg)
Length: Metre (m)
Time: Second (s)
Force: Newton (N)
Pressure: Pascal (Pa)

Input Values

1 Pound = 0.45359237 kg
1 Foot = 12 ins
1 Inch = 0.0254 m
1 Square Foot = (12 x 0.0254 m) x (12 x 0.0254 m) = 0.09290304 m²
Acceleration = Standard Gravity = 9.80665 m/s²

Calculation

1 Pound Force = 0.45359237 kg x 9.80665 m/s² = 4.448221615 N
1 psf Pressure = 4.448221615 N / 0.09290304 m² = 47.88025898 Pa

psi Alternate Descriptions

These are the different versions used for identifying psi that you may find elsewhere.

Pounds Per Square Foot
Pound Per Square Foot
Pounds Force Per Square Foot
Pound Force Per Square Foot
Pounds Per Square Feet
Pound Per Square Feet
Pounds Force Per Square Feet
Pound Force Per Square Feet
psf
pfsf
lb/ft²
lbf/ft²
lb/sq ft
lbf/sq ft
lb/ft^2
lbf/ft^2 lbs/ft²
lbsf/ft²
lbs/sq ft
lbsf/sq ft
lbs/ft^2
lbsf/ft^2

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