| Reference | Yards (yd) | Furlongs (fur) |
|---|---|---|
| A sheet of A4 paper (long side) | 0.324803 yd | 0.00147638 fur |
| Average adult human height | 1.85914 yd | 0.00845065 fur |
| A football pitch (length) | 114.829 yd | 0.521952 fur |
| A marathon | 46145 yd | 209.75 fur |
| Height of Mount Everest | 9677.38 yd | 43.9881 fur |
The yard is a unit of length equal to exactly 0.9144 metres, or three feet. The symbol is yd. It is the base unit of the imperial and United States customary length systems, with the foot and inch defined as fractions of it.
That relationship is the reverse of what most people assume. Since 1959 the yard has been defined against the metre, and the foot and inch follow from it, so every imperial length unit is ultimately derived from an SI definition. The International Yard and Pound Agreement fixed the value at 0.9144 metres exactly, reconciling small differences between the American and British yards that had persisted for decades.
The origin of the name is uncertain. Old English gierd meant a rod or measuring stick. The frequently repeated story that Henry I defined the yard as the distance from his nose to his outstretched thumb is not supported by contemporary evidence, though it has proved durable. A physical standard yard bar was maintained in London from 1760, and its destruction in the 1834 Palace of Westminster fire forced a lengthy reconstruction from surviving copies.
Sport keeps the unit prominent. An American football field is 100 yards between goal lines, and the game's vocabulary is built around yardage. Golf course distances are marked in yards in Britain and the United States. Cricket sets the distance between wickets at 22 yards, a figure inherited from the surveyor's chain.
Fabric and carpet are sold by the yard in the United States, and textile widths are quoted in inches alongside. Landscaping materials such as topsoil and gravel are sold by the cubic yard, which is 27 cubic feet or about 0.7646 cubic metres.
Its cube runs the construction trade in North America. Concrete is ordered, delivered and billed by the cubic yard, about 0.765 cubic metres, and a standard mixer truck carries eight or nine of them; excavation, gravel, topsoil and demolition waste are all quoted the same way. Golf keeps the linear unit just as firmly, with every hole on every scorecard measured in yards and every club sold on the distance it carries, so a player who reads a shot as a hundred and fifty yards is using a measurement the rest of the game's arithmetic depends on. Between them the two uses make the yard unlikely to disappear.
One yard equals 3 feet, 36 inches, or 0.9144 metres exactly. It is a little shorter than a metre, by about 8.4 centimetres.
The furlong is a unit of length equal to 220 yards, 660 feet, or exactly 201.168 metres. It is one eighth of a mile and ten chains.
The name is a contraction of the Old English furh lang, meaning furrow long, and describes the distance a team of oxen could plough before needing rest. That practical origin fixed the length of a medieval strip field, and the furlong therefore predates the mile's English definition. When the Roman mile of 5000 feet was reconciled with English land measurement, the mile was lengthened to 5280 feet so that it would contain a whole number of furlongs. The awkward figure that generations of schoolchildren have memorised is a direct consequence of preserving the older agricultural unit.
Horse racing is where the furlong remains in active daily use. Race distances in Britain, Ireland, the United States and much of the racing world are stated in miles and furlongs, so a race described as one mile two furlongs covers 2010 metres. Sectional times are recorded furlong by furlong, and commentary is built around the unit. Distance markers along the rail count down the remaining furlongs to the finish.
The furlong's relationship to area explains its persistence in older records. An acre was originally defined as one furlong long by one chain wide, the area a team could plough in a day. This is why an acre is a long thin rectangle rather than a square, and why its modern value of 43,560 square feet looks arbitrary.
Outside racing the unit is largely archaic, though it appears in some historical land deeds and in the occasional legal description. Computing folklore keeps it alive in the furlong per fortnight, a deliberately absurd unit of speed used to make a point about dimensional analysis.
It is the reason the acre has the shape it does. An acre was defined as one furlong long by one chain wide, 220 yards by 22, and that long thin rectangle is exactly what a team of oxen could plough in a day without turning more often than necessary. The proportion of ten to one is preserved in the ridge and furrow patterns still visible from the air across the English Midlands, and in field boundaries that have outlasted every plough that made them. The furlong therefore survives less as a measurement than as a shape written into the landscape.
One furlong equals 220 yards, 10 chains, one eighth of a mile, or 201.168 metres.