Key factors in cylinder length

Door thickness
Mortise lock position in door leaf
Faceplate thickness door handle
Faceplace thickness of inside door handle
Cylinder length calculation formula

Tltal length=door thickness + faceplate thickness of outside door and inside door handle

Outside length=faceplate thickness of outside door handle + dinension of mortise lock outside center position

Iutside length=faceplate thickness of outside door handle + dinension of mortise lock inside center position