There is no definitive answer to this question as it depends on the particular door in question and the purpose for which it is being used. In general, however, most doors should not be allowed to open more than 90 degrees, as this can pose a safety hazard. Doors that open too far can easily become jammed, preventing them from being closed properly. This can create a gap that allows people or animals to enter a space that they should not have access to. In addition, doors that open too far can also be a tripping hazard.