The hand is a non-SI unit of measurement of length, now normally used only for the measurement of the height of horses in some English-speaking countries, including Australia, Canada, the United Kingdom and the United States. With origins in ancient Egypt, it was originally based on the breadth of a human hand. It is today equal to four inches, and thus, following the adoption of the international inch in 1959, it is equal to exactly 10.16 centimetres. It may be abbreviated to "h" or "hh". Although measurements between whole hands are usually expressed in what appears to be decimal format, the subdivision of the hand is not decimal but is in base 4, so subdivisions after the radix point are in quarters of a hand, which are inches. Thus, 62 inches is fifteen and a half hands, or 15.2 hh (normally said as "fifteen-two", or occasionally in full as "fifteen hands two inches")
"Hands" may be abbreviated to "h", or "hh". The "hh" form is sometimes interpreted as standing for "hands high." When spoken aloud, hands are stated by numbers, 15.0 is "fifteen hands", 15.2 is alternately "fifteen-two" or "fifteen hands, two inches," and so on.
To convert inches to hands, the number in inches is divided by four, then the remainder is added after the radix point. Thus, a horse that measures 60 inches is 15 hands high (15 x 4 = 60) and a horse halfway between 15 and 16 hands is 15.2 hands, or 62 inches tall (15 x 4 + 2 = 62) Because the subdivision of a hand is a base 4 system, a horse 64 inches high is 16.0 hands high, not 15.4.  A designation of "15.5 hands"is not not halfway between 15 and 16 hands, but rather reads 15 hands and five inches, an impossibility in a base 4 radix numbering system, where a hand is four inches.
Ancient Egypt 
The hand, sometimes also called a handbreadth or handsbreadth, is an anthropic unit, originally based on the breadth of a male human hand, either with or without the thumb, or on the height of a clenched fist.
On surviving Ancient Egyptian cubit-rods, the royal cubit is divided into seven palms of four digits or fingers each. Five digits are equal to a hand, with thumb; and six to a closed fist. The royal cubit measured approximately 525 mm, so the length of the ancient Egyptian hand was about 94 mm.
|Name||Egyptian name||Equivalent Egyptian values||Metric equivalent|
|7 palms or 28 digits||525 mm|
|Fist||6 digits||108 mm|
|Hand||5 digits||94 mm|
|4 digits||75 mm|
|1/4 palm||19 mm|
Biblical use 
In Biblical exegesis the hand measurement, as for example in the Vision of the Temple, Authorized Version Ezekiel 40:43, is usually taken to be palm or handbreadth, and in modern translations may be rendered as "handbreadth" or "three inches".
The hand is a traditional unit in Britain. It was standardised at four inches by a statute of King Henry VIII in 1541, but some confusion between the various types of hand measurement, and particularly between the hand and the handsbreadth, appears to have persisted. Phillips's dictionary of 1706 gives four inches for the length of the handful or hand, and three inches for the handsbreadth; Mortimer gives the same, three inches for the Hand's-breadth, and four for the "Handful, or simply, Hand", but adds
"The hand among horse-dealers, &c. is four-fingers' breadth, being the fist clenched, whereby the height of a horse is measured"
thus equating "hand" with both the palm and the fist. Similarly, Wright's 1831 translation of Buffon mentions "A hand breadth (palmus), the breadth of the four fingers of the hand, or three inches", but the Encyclopædia Perthensis of 1816 gives under Palm (4): "A hand, or measure of lengths comprising three inches".
Use in measuring horses 
Today the hand is used for measurement of the height of horses, ponies, and other equines. It is used in several countries, including the U.S. and some that have formally adopted the metric system, such as Australia, Canada, Ireland and the UK. In most of the world, including continental Europe, and in all FEI-regulated international competition, horses are measured in metric units, usually metres or centimetres. In some countries, such as South Africa, measurements may be given in both hands and centimetres.
In those countries where hands are the usual unit for measuring horse height, inches rather than hands are commonly used in the measurement of miniature horses, miniature ponies, miniature mules, donkeys, and Shetland ponies.
A horse is measured from the ground to the top of the highest non-variable point of the skeleton, the withers. For official measurement, the spinous process of the fifth thoracic vertebra may be identified by palpation, and marked if necessary. Miniature horses, but not miniature ponies, may be measured at the base of the last true hairs of the mane rather than at the withers.
For international competition regulated by the Fédération Equestre Internationale (FEI) and for USEF competition in the US, a horse can be measured with shoes on or off. In the United Kingdom much official measurement of horses is overseen by the Joint Measurement Board (JMB). For JMB purposes, the shoes must be removed before measurement and the hooves correctly prepared for shoeing.
See also 
- "The "Hand" Measurement for Horses". Ministry of Agriculture, Food and Rural Affairs, Ontario, Canada. Retrieved June 2011.
- Brander, Michael (1971). The Complete Guide to Horsemanship. London: A & C Black. p. 444. ISBN 0-7136-1701-2. p.409
- How big is a hand?
- Hand Conversion
- How to Measure a Horse | Horse Height and Weight
- Shlei, "Just how tall is a hand?" Measuring Equines, The American Donkey and Mule Society, accessdate = 2007-05-19
- Measure Horse Height Accurately
- Good, J.M., O. Gregory, N. Bosworth (1813). Pantologia: A new cyclopaedia, comprehending a complete series of essays, treatises, and systems, alphabetically arranged; with a general dictionary of arts, sciences and words, the whole presenting a distinct survey of human genius, learning and industry; illustrated with engravings, those on history being from original drawings by Edwards and others. London: Kearsley. "Hand (2)"
- Selin, Helaine, ed. (1997). Encyclopaedia of the History of Science, Technology and Medicine in non-Western Cultures. Dordrecht: Kluwer. ISBN 978-0-7923-4066-9.
- Clagett, Marshall (1999). Ancient Egyptian Science, A Source Book. Volume 3: Ancient Egyptian Mathematics. Philadelphia: American Philosophical Society. ISBN 978-0-87169-232-0.
- Lepsius, Richard (1865). Die altaegyptische Elle und ihre Eintheilung (in German). Berlin: Dümmler.
- Ezekiel 40:43 New International Version
- Ezekiel 40:43 New Century Version
- Mortimer, Thomas (1810). A general dictionary of commerce, trade, and manufactures: exhibiting their present state in every part of the world; and carefully comp. from the latest and best authorities. London: R. Phillips.
- Phillips, Edward, John Kersey (ed.) (1706) The new world of words: or, Universal English dictionary. Containing an account of the original or proper sense, and various significations of all hard words derived from other languages. Together with a brief and plain explication of all terms relating to any of the arts and sciences; to which is added, the interpretation of proper names The sixth edition, revised ... With the addition of near twenty thousand words London
- Le Clerc, George Louis, Comte de Buffon; (trans.) John Wright (1831). A natural history of the globe: of man, of beasts, birds, fishes, reptiles, insects and plants Volume 5. Boston; Philadelphia: Gray and Bowen; Thomas Desilver, Jr.
- [n.a.] (1816). Encyclopædia Perthensis; or Universal Dictionary of the Arts, Sciences, Literature, etc., intended to supersede the use of other books of reference, Volume 16.
- "Show Rules. Standards of Excellence: Miniature & Small Horse". Australian Miniature Horse & Pony Registry. Retrieved July 2011.
- "About Miniature Mules". The American Miniature Mule Society. Retrieved July 2011.
- "The Donkey". Government of Alberta: Agriculture and Rural Development. Retrieved July 2011.
- Edwards, Elwyn Hartley (1994). The Encyclopedia of the Horse (1st ed.). London: Dorling Kindersley. ISBN 0-7513-0115-9. p.176
- "JMB measurement". The Joint Measurement Board. Retrieved June 2011.