Various units of length that take their name from the Roman palm, although mostly about four times larger. The word “palmo” occurs in Spanish, Portuguese and Italian. Many different local values occurred in each language, and they changed with time.



In Spain the palmo was generally ⅛th estado or ¼th vara, in the 20ᵗʰ century, 23.2 centimeters.

19ᵗʰ century (Doursther, 1840, pg 374)
Region or City   Value,
Alicante   226.250
Aragon ¼ vara of Saragosse 192.750
Barcelona   about 194
Cadiz   208.75
Castille palmo mayor about 208.75
palmo menor or palmo de ribera about 69.5833
Saragossa   192.750
Valencia   226.7500  (Kelly, 232.5760)



In Portugal, at least as early as 1575 – 20ᵗʰ century, the palmo de craveira, = ¹⁄₁₀ braça, exactly 22 centimeters¹ (about 8.66 inches). link to a table of Portuguese units of length

Another unit, the palmo de craveira avantejado (palmo of good measure), used for cloth, was about 226.875 millimeters, an additional ¼ pollegada for each palmo.

The palmo da Junta, 1756 – ?, established by the Junta de Commercio, a committee of merchants, for the purpose of standardizing measures used in trade with Portugal's colonies, was about 20.0200 centimeters.

In Brazil globe icon, the palmo was about 21.740 centimeters.

1. Mappas das Medidas do Novo Systema Legal comparadas com as Antigas nos Diversos Concelhos do Reino e Ilhas.
Lisbon: Imprensa Nacional, 1868.
Page 298.




Various units of length in Rome opens a new page containing a chart that shows relationships between this unit and other units in its system:


In Naples, 1838, the palmo had the same value, which corresponded to an old standard kept at the Castel Capuano, but 8 palmi = 1 canna. Abolition of the canna was proposed, but instead it was decimalized, 10 palmi = 1 canna.

In the Kingdom of the Two Sicilies, by an ordinance of 6 April 1840, ¹⁄₇₀₀₀ of the average distance subtended by 1 minute of arc on the Earth's meridian, = ¹⁄₇₀₀₀th of a miglio. 100 meters = 378 palmi, making the palmo 26.455 centimeters.

Naples 262.0145

In Sicily, Palermo, 242.7836 cm, Messina 264.1576 mm

Carrara (for measuring marble) = 9 ?/? inches, 243.8336

Florence, 291.800

Livorno, 291.800

Pisa 291.800

In 1803,  Milan and the entire Kingdom of Lombardy-Venice adopted the name palmo for the decimeter (about 3.94 inches).

Majorca 195.500



La canna del pano di Napoli si è palmi viij che palmi viij fanno una canna di Firenze.

The canna of cloth of Naples is 8 palmi, which 8 palmi make 1 Florentine canna.

Chiarini, 1481.


La base dell' intero sistema il palmo è settemillesima parte di un minuto primo del grado medio del meridiano terrestre, ovvero la settemillesima parte del miglio geografico d'Italia e del miglio nautico di 60 a grado medio del meridiano medesimo. Esso sarà diviso in parti decimali e dieci palmi costituiranno la canna. La canna lineare, la canna quadrata e la canna cubica sono le unità di misura di lunghezza, di superficie e di solidità per tutti gli usi. La prima è uguale a 10 palmi lineari, la seconda a cento palmi quadrati e la terza a mille palmi cubici. Rapporto col sistema metrico decimale. Cento metri uguagliano 378 palmi, cioè il metro è equivalente a palmi 3,78 ed il palmo a metri 0,26455.

The base of the entire system, the palmo is a 7000th part of a degree of the terrestial meridian, or rather the 7000th part of the miglio geografico of Italy and of the nautical mile It shall be divided decimally, and 10 palmi constitute the canna. The linear canna, the square canna and the cubic canna shall be the units of measurement for length, for area and for capacity for all uses. The first is equal to 10 linear palmi, the second to 100 square palmi, and the third to 1000 cubic palmi. Relationship with the decimal metric system. One hundred meters is equal to 378 palmi, that is to say, the meter is equal to 3.78 palmi and the palmo to 0.26455 meter.

Carlo Afan de Rivera.
Tavole di Riduzione dei Pesi e delle Misure delle Due Sicile in quelli statuite dalla legge de'6 aprile del 1840.
Naples: Dalla Stamperia e Cartiere del Fibreno, 1840.


...lungha palmi 1040, cioè canne 104, e larga palmi 360, che sono canne 36...

...1040 palmi long, that is, 104 canne, and 360 palmi wide, which is 36 canne...

Giorgio Vasari.
Antonio da Sangallo architetto fiorentino.
in Le vite dé piu èccellenti pittori, scultori e architettori...
Florence, 1550.


In Ecuador, 20ᵗʰ century, approximately 21 centimeters.


In Libya, 20ᵗʰ century, a unit of length used for textiles = 25 centimeters¹. In the 19th century, it was ¹⁄₃ of a dra or Turkish pic, 223.6853 mm.

1. United Nations, 1966.


In Corsica, 250.1714 millimeters.


In Costa Rica, 19ᵗʰ century, a unit of length = ¼ vara, = 20.9 centimeters. A synonym for the cuarta.

[Costa Rica. Ministerio de formento.]
Medidas y pesas del sistema métrico, y tablas de equivalencia con las antiguas.
San José de Costa Rica: Imprenta nacional, 1885.


In Mexico, a unit of length = ¼ vara, about 209.5 millimeters. A synonym for the cuarta. According to Galván Riviera, this division was modeled on the division of the vara of Toledo.

Galván Riviera, 1844. Excerpt in Spanish with English translation.


In Sardinia, 262.350 mm opens a new page containing a chart that shows relationships between this unit and other units in its system


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