The barleycorn is based on the length of a barley grain.
General information
Unit systemImperial units
Unit ofLength
1 barleycorn in ...... is equal to ...
   Imperial units   1/3 in
   SI units   8.47 mm
A chart of Imperial and United States customary units.

The barleycorn is an English unit of length[1] equal to 13 of an inch (i.e. about 8.47 mm). It is still used as the basis of shoe sizes in English-speaking countries.


Under the 1300 Composition of Yards and Perches, one of the statutes of uncertain date that was notionally in force until the 1824 Weights and Measures Act, "3 barly cornes dry and rounde"[2][3] were to serve as the basis for the inch and thence the larger units of feet, yards, perches and thus of the acre, an important unit of area. The notion of three barleycorns composing an inch certainly predates this statute, however, appearing in the 10th-century Welsh Laws of Hywel Dda.

In practice, various weights and measures acts of the English kings were standardized with reference to some particular yard-length iron, brass, or bronze bar held by the king or the Royal Exchequer. The formal barleycorn was 1108 of its length.[4]

As modern studies show, the actual length of a kernel of barley varies from as short as 0.16–0.28 in (4–7 mm) to as long as 0.47–0.59 in (12–15 mm) depending on the cultivar.[5][6] Older sources claimed the average length of a grain of barley was 0.345 in (8.8 mm), while that of a grain of "big" was 0.3245 in (8.24 mm).[7]

See also


  1. ^ "Barley corn", Britannica, Edinburgh, 1769
  2. ^ Ruffhead, Owen (1765). Statutes at Large |From the second year of the reign of King George the Third | And an Appendix consisting of O[illegible]s and Curious Acts, some of which were never [b]efore printed. Vol. 9. Printed by M. Baskett. p. A421. OCLC 22642053. Retrieved 12 February 2012. Ordinatum est quod tria grana ordei sicca & rotunda faciunt pollicem... [Let it be declared that 3 grains of barley, dry and round, make an inch...]
  3. ^ Fowler, W. (1884). "On the ancient terms applicable to the measurement of land". Transactions. Vol. XVI. Royal Institution of Chartered Surveyors. p. 277. Retrieved 8 January 2012.
  4. ^ Zupko, Ronald Edward (1977). British Weights and Measures: A History from Antiquity to the Seventeenth Century. Madison, Wisconsin: University of Wisconsin Press. p. 21. ISBN 978-0-299-07340-4.
  5. ^ Ullrich, Steven E. (2011). Barley: Production, Improvement, and Uses. p. 454.
  6. ^ Sýrkorová, Alena; et al. (2009). "Size Distribution of Barley Kernels" (PDF). Czech Journal of Food Sciences. 27 (4): 249–58. doi:10.17221/26/2009-CJFS.
  7. ^ "Brewing". Supplement to the Encyclopædia Britannica. Vol. 2. Edinburgh. 1824. p. 462.