Tire pressure gauge

A tire pressure gauge includes a tubular housing, an air ventilating member dividing the housing into receiving and coupling chambers, a flexible diaphragm disposed in the receiving chamber and having a raised portion which is movable in response to an air pressure introduced into the receiving chamber through the coupling chamber, which is coupled to a tire valve, so as to move a pressure indicating member relative to a cap in order to indicate the tire pressure condition, an adjustable member adjustably disposed in the cap, and a biasing member disposed between the pressure indicating member and the adjustable member so as to correct the position of the pressure indicating member.