According to the theory of geomantic omen, the height of any door in a room should not exceed the height of the gate.
The height of the kitchen door is generally 2. 1 m, 2.4 m and 2.7 m, and the width of the door is generally 0.9 m, 1.2 m and 1.5 m, which is not very strict and can be adjusted according to actual needs.