Yard

From Wikipedia, the free encyclopedia

For other uses, see Yard (disambiguation).

1 yard =
International units
0.914 m	914.4×10⁻⁶ km
914.4 mm	9.144×10⁹ Å
6.112×10⁻¹² AU	96.652×10⁻¹⁸ LY
US customary / Imperial units
36 in	3 ft
1 yd	568.182×10⁻⁶ mi

A yard (abbreviation: yd) is the name of a unit of length in a number of different systems, including English units, Imperial units, and United States customary units. Its size can vary from system to system. A yard is three feet or 36 inches. The yard is often used to express distances. A corresponding unit of area is the square yard. The most commonly used yard today is the international yard which by definition is equal to 0.9144 metre. The yard is used as the standard unit of field length measurement in both the American and Canadian games of football (the latter despite the fact that Canada is almost entirely otherwise metric).

[edit] Equivalence to other units of length

1 international yard is equal to:

0.5 fathom (1 fathom is equal to 2 yards)
3 feet (1 foot is a third of a yard)
36 inches
0.9144 metre (1 metre is equal to about 1.0936 international yards)

The early yard was divided by the binary method into two, four, eight, and sixteen parts called the half-yard, span, finger, and nail. Two yards are a fathom.

[edit] Historical origin

The yard derives its name from the word for a straight branch or rod, although the precise origin of the measure is not definitely known. Some believe it derived from the double cubit, or that it originated from cubic measure, others from its near equivalents, like the length of a stride or pace. One postulate was that the yard was derived from the girth of a person's waist, while another claim held that the measure was invented by Henry I of England as being the distance between the tip of his nose and the end of his thumb. These are believed to be more likely standardising events than inventing of the measure.