A school flag pole ranges in height from 20 feet to 45 feet. Most flag poles intended for public or institutional display generally fall within this range.
Flag poles for residential use generally fall between 15 feet and 25 feet in height. This applies to flag poles mounted in-ground as opposed to those attached to buildings.
The length of the flag itself depends on the length of the flag pole. The correct ratio is at least 1:4 or one quarter. This means the length of the flag should be at least one quarter the height of the pole. For example, a 20-foot pole would carry at least a 5-foot flag.