Refer to figure.
PRESSURIZATION SYSTEMS​​​​
For aircraft with passenger cabins, the maximum cabin altitude of an aircraft must be limited to between 6000 and 8000 ft. At this altitude, the air will provide sufficient oxygen for normal use.

Cabin Differential Pressure. Cabin pressure - ambient air pressure
The difference in pressure between the cabin pressure and the ambient pressure (the pressure in the area immediately surrounding the aircraft). Flying an aircraft at high altitude, with the cabin pressure set to a lower altitude, results in a pressure difference acting on the structure of the aircraft fuselage (hoop stresses). The maximum permissible cabin differential pressure for a transport aircraft is generally between 7 an 9 psi, however it may vary based on the fuselage design strength, and will limit the aircraft’s operational ceiling and its associated maximum cabin altitude.

• According to the table provided, at 41 000 ft the pressure is approx 2.59 psi. The average maximum cabin altitude is usually maintained at 8000 ft, where pressure is 10.92 psi => ie.10.92 - 2.59 = 8.33.