There are 36 inches in 1 yard, which is equal to 3 feet. A yard was once believed to be the length of the average stride. The inch represents 1/12 foot. The inch is an English word that derives from the Latin word "uncia," which means one-twelfth.
Measurements were once calculated against parts of the human body. An inch was the width of a man's thumb. A yard was the average length of a man's belt. The English king Henry I announced that a yard was the length from the end of his outstretched arm to his nose. In 1959, it was internationally agreed that the inch equalled 25.4 millimeters.