Pounds per square foot
Pounds per square foot (psf) is a unit used in the United States, United Kingdom and some other countries that use the Imperial system. It is the pressure of a one pound on an area of one square foot.
Pascals
Pascals (Pa) are the SI units of pressure named after the French mathematician Blaise Pascal. It is defined as one newton per square meter (N/m²). Since the pascal is a relatively small unit, kilopascals (kPa), megapascals (MPa), and gigapascals (GPa) are often used for practical applications.