Pressure is defined as the force acting normally (perpendicularly) per unit area .
The SI units for pressure is newton per metre squared (N/m2).
One Nm-2 is known as one Pascal (Pa).
Pressure = normal force / area or pressure = thrust / area . Another unit for measuring pressure is the bar. 1 bar = 105 N/m2. 1 millibar = 100 N/m2.