[[Image:Britanski merki za dalzhina Grinuich 2005.jpg|thumb|Standard lengths on the wall of the [[Royal Observatory, Greenwich]], [[London]] - 1 yard (3 feet), 2 feet, 1 foot, 6 inches ({{frac|2}} foot), and 3 inches. The separation of the inside faces of the markers is exact at an ambient temperature of 62°F (16{{frac|2|3}}°C) and a rod of the correct measure, resting on the pins, will fit snugly between them.<ref>{{citation|last = Bennett | first = Keith | editor = Bucher, Jay L. | title = The Metrology Handbook | publisher = American Society for Quality Measurement | location = Milwaukee, WI | year = 2004 | page = 8 | isbn = 978-0-87389-620-7}}.</ref><ref>{{cite book|author1=Great Britain Parliament, House of commons, Select committee on weights and measures|last2=Ewart|first2=William|title=Report from the Select committee on weights and measures|url=http://books.google.com/books?id=wI7nAAAAMAAJ&pg=PA113|accessdate=31 March 2012|year=1862|pages=112–3}}</ref>]]
[[పొడవు]] యొక్క కొలతను కొలుచుటకు ఒక ప్రమాణం '''గజము'''. గజమును ఆంగ్లంలో యార్డ్ అంటారు. యార్డ్ యొక్క సంక్షిప్త రూపం yd. గజము అనగా 3 [[అడుగులు]] లేదా 36 [[అంగుళాలు|అంగుళాలకు]] సమానం.
