The American Kennel Club (AKC) determines the accepted breed standard for German Shepherds in the United States. Here is a shortened version of the AKC breed standards of German Shepherds:
Overall strong, agile, well-muscled, and full of life
Longer than tall, deep-bodied, with an outline of smooth curves
Males 24 to 26 inches; females 22 to 24 inches at the shoulders
Noble, strong, chiseled head; long muzzle parallel to back of skull
Almond-shaped eyes
Moderately pointed ears facing forward and set parallel to one another
Black nose
Scissors bite
Shoulders are higher than back, which is level and straight
Sternum reaches to elbows; moderately tucked-up loin
Tail is bushy, set low, and hanging in slight curve
Shoulder blades obliquely angled with well-angulated wrists
Broad thigh with a right angle between upper and lower thigh
Double coat of medium length, with dense, straight, harsh outer coat
Most colors are permitted (except for white); rich colors preferred
Gait is ground-covering and effortless
Temperament is confident, fearless but aloof; eager, alert, and willing to work