The vara (meaning rod or pole; however not at all similar to the unit of that name in English-language-based units of measurement; often rendered yard in English, and a name often used to render the English word "yard" into Spanish) was a unit of length or distance in the old Castilian system of units. Since no actual Castilian standards are definitively known by the present day, the only way of determining the length of any Old Castilian unit would be to measure something in modern terms whose length was given by the Castilians in their units. And because this procedure does not give us any clue to which unit may have been the base unit and which were subsidiary units, this distinction really does not apply to the Old Castilian units here given, so all the units really have equal status. However, most references appear to have treated the vara as the base unit, expressing other units in terms of the vara.
Relation to other Old Castilian units
- Common to all sources:
- 3 pies (Old Castilian feet) = 1 vara
- According to Cardarelli:
- According to Woolhouse:
- 4 varas = 1 estadal
Value in terms of modern units
Cardarelli, in his tabulation, gives the value of 0.835905 m for the length of the vara, equal to 2.74247 ft = 0.914157 yd . This value is given in Wikipedia as well. Woolhouse gives the slightly larger value of 33.384 in (84.795 cm). Other values have been found in the literature as well, differing slightly from these.
- Cardarelli, François (1998). Scientific Unit Conversion. Berlin, Heidelberg, New York: Springer-Verlag. ISBN 3-540-76022-9.
- Woolhouse, Wesley Stoker Barker (1864). London, England: Virtue Brothers & Co. (Reprinted by Kessinger Publishing).
- The variable vara (length of the vara in Spain and various former colonies)