Roman Cubits to Kilometers (cubitum to km)

1 Roman cubit equals 0.000444 kilometers exactly.

1 Roman cubit = 0.000444 kilometers

How to convert Roman cubits to kilometers

To convert Roman cubits to kilometers, multiply the number of Roman cubits by 0.000444. This factor is exact. To go the other way, multiply kilometers by 2,252.252252 (rounded).

kilometers = Roman cubits × 0.000444

Example: 10 Roman cubits = 0.00444 kilometers.

Approximate value. Standards for the Roman cubit varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.

About these units

Roman Cubit (cubitum)

Ancient RomanHistorical unit (no longer in standard use)Approximate value

One and a half Roman feet, about 44.4 cm.

Cubitum was the Latin word for elbow, and it came from a verb meaning to lie down or recline, the root of the English cubit. Roman writers such as Vitruvius defined it as one and a half Roman feet, or six palm widths, which gives about 444 mm. That is the figure used here. It was meant to span roughly the length of the forearm from the elbow to the fingertips.

Compared with other ancient cubits it was short. The Egyptian royal cubit survives on rods measuring about 523 to 529 mm, and Wikipedia says ancient cubits generally ranged from about 44.4 to 52.9 cm, so the Roman one sits at the bottom of that range. Romans also used a separate, longer ulna of about 120 cm. In a modern setting the Roman cubit is a little over 17 inches.

1 Roman cubit = 0.444 meters (approximately).

Sources: Wikipedia: Cubit; Wikipedia: Ancient Roman units of measurement

Kilometer (km)

Metric (SI)Current unit

1,000 meters. The standard unit for road distances in most countries.

A name for 1,000 meters took a while to settle. In 1793 France's National Convention made the metre the sole French unit of length, and the first proposed name for the thousand-metre multiple was millaire. Everyday French usage then leaned on the myriametre, 10,000 meters, well into the 1800s. The Netherlands adopted the kilometre in 1817, under the local name mijl, and made it the only official unit of that size in 1867. In 1935 the CIPM dropped the myria- prefix, which left the kilometre as the standard unit for road-scale distances.

Kilo- is the SI prefix for a thousand, and the kilometre is now the preferred unit for land distances in most of the world, with the United States, the United Kingdom and Liberia among those that still use the mile. One kilometre is about 0.621 mile. The main span of Lisbon's 25 de Abril Bridge, at 1.013 km, gives a sense of the scale. Even its pronunciation has been argued over: in 1970 Australia's Metric Conversion Board made stress on the first syllable official, although Prime Minister Gough Whitlam argued for stress on the second. Military slang in several countries calls it a klick.

1 kilometer = 1,000 meters (exactly).

Sources: Wikipedia: Kilometre; Wikipedia: Metric prefix; BIPM: history of the metre

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