Yard
Length · Also called: virga, ulna
That is
91.44 cm
1 yard (imperial)
The other way round: 1 m is 1.0936 yards.
- Period: 1959 to today
- Region: the UK
Values
| Value | That is | Period | Used for |
|---|---|---|---|
| imperial | 91.44 cm | 1959 to today | the UK |
| standard bronze barThe 1922 determination of the 1845 bar. A fresh measurement in 1963 gave 0.9143969 m, because the metal was slowly contracting. | 91.44 cm | 1824 to 1959 | the UK |
What the unit was used for
The yard is the base of imperial length and is now defined as exactly 0.9144 metre.
Until 1959 it was an object: a bronze bar made in 1845 to replace the parliamentary standard lost when the Houses of Parliament burned in 1834.
Repeated comparisons at the National Physical Laboratory showed the bar shrinking by roughly one part per million every 23 years, from 0.91439841 m in 1922 to 0.9143969 m in 1963.
That drift is exactly why six English-speaking nations agreed in 1959 to define the yard against the metre instead of against a lump of metal.
In the system
1 yard = 3 feet = 36 inches
A story you will often hear
The yard is often said to have been fixed as the distance from Henry I’s nose to the tip of his outstretched thumb.
What the evidence shows: No contemporary source records it. The story has been repeated for centuries without support and belongs to folklore, not to the history of the unit.