Length & Distance

Standardised in 1324 by King Edward II as the length of three dry grains of barley laid end to end.

1/3 inch = 8.47 millimetres

The diameter of a gun barrel, expressed as the number of spherical lead balls of that diameter which together weigh one pound.

12-bore = 18.5 mm; 20-bore = 15.6 mm

One tenth of a nautical mile, and originally the working length of a ship’s anchor cable.

185.2 metres = 607.6 feet

Introduced by Edmund Gunter in the 17th century using a physical surveying chain. A cricket pitch is one chain long.

22 yards = 20.1168 metres

An ancient historical length unit based on the physical length of a forearm.

18 inches = 0.4572 metres

A traditional cloth-measuring length of 45 inches, descended from the arm-based measures of the medieval textile trade.

45 inches = 1.143 metres

The Scots counterpart of the English rod, being six Scots ells, and the building block of both the Scots mile and the Scots acre.

Approx. 6.2 yards = 5.67 metres

Derived from Old English for outstretched arms, traditionally used for measuring water depth.

6 feet = 1.8288 metres

A universal traditional length unit historically based on the human foot.

12 inches = 30.48 centimetres

Originally the length of a furrow in one acre of ploughed land; survives in horse racing.

220 yards = 201.168 metres

Exclusively used to measure the height of horses from the ground to the withers.

4 inches = 10.16 centimetres

A traditional length unit historically derived from the width of a human thumb.

2.54 centimetres

Two thousand two hundred and forty yards, the longest of the miles used across these islands.

2,240 yards = 2.048 kilometres = 1.27 English miles

Seven yards, or twenty-one feet, against the English perch of five and a half yards.

7 yards = 21 feet = 6.4008 metres

An ancient unit representing the estimated distance a person could walk in one hour.

3 miles = 4.828 kilometres

A fine measure of diameter surviving in two distinct trades, at two quite different sizes.

Watchmaking: 2.2558 mm. Buttons: 0.635 mm (1/40 inch)

Derived from Gunter’s surveying chain, where 100 links equal one chain (7.92 inches each).

7.92 inches = 0.201168 metres

Standardised to exactly 5,280 feet by the English Parliament in 1593.

1,760 yards = 1.60934 kilometres

The finest subdivision of the cloth trade, being two and a quarter inches, or one sixteenth of a yard.

2.25 inches = 5.715 centimetres

Based on Earth’s circumference, equal to exactly one minute of latitude.

1.15078 statute miles

A traditional length unit representing a full two-step stride (5 feet).

5 feet = 1.524 metres

A traditional land surveying unit (16.5 feet / 5.5 yards), synonymous with Pole and Rod.

16.5 feet = 5.0292 metres

A traditional land surveying unit (16.5 feet), synonymous with Perch and Rod.

16.5 feet = 5.0292 metres

An ancient microscopic length unit defined as one-quarter of a barleycorn.

1-2 millimetres

A traditional surveying length (16.5 feet), synonymous with Perch and Pole.

16.5 feet = 5.0292 metres

Scotland’s standard ell, running to about 37 inches, and the unit from which the fall, mile and acre were all derived.

Approx. 37 inches = 94 centimetres

Scotland’s own mile, running to about 1,976 yards, appreciably longer than the English statute mile.

Approx. 1,976 yards = 1,807 metres

An ancient length unit measuring the distance from thumb to little finger on a spread hand (9 inches).

9 inches = 0.2286 metres

One-thousandth of an inch, heavily relied upon in manufacturing for precision component metrics.

0.001 inches = 0.0254 millimetres

The width of a thumb at the knuckle, taken as roughly one inch, and the body measure from which the inch descends.

Width approx. 2–2.3 cm; top joint approx. 2.5 cm

Traditional length famously said to represent the distance from King Henry I’s nose to his thumb.

3 feet = 0.9144 metres