One cubic metre of concrete (representing the world annual production per inhabitant)

The cubic metre (US spelling: cubic meter, symbol: m³) is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère. Another alternative name, not widely used any more, is the kilolitre.

Conversions[link]

1 cubic metre is equivalent to:

• 1,000 litres (exactly);^[1][2]
• ~35.3 cubic feet (approximately)
  • 1 cu ft = 0.028316846592 m³
• ~1.31 cubic yards (approximately)
  • 1 cu yd = 0.764554857984 m³
• ~6.29 oil barrels (approximately)
  • 1 oil bbl = 0.158987294928 m³
• ~264.17 fluid gallons (approximately)

A cubic metre of pure water at the temperature of maximum density (3.98 °C) and standard atmospheric pressure (101.325 kPa) has a mass of 1,000 kg, or one tonne. At 0 °C, the freezing point of water, a cubic metre of water has slightly less mass, 999.972 kilograms.

It is sometimes abbreviated to cu m, m3, M3, m^3, m**3, CBM, cbm when superscript characters or markup cannot be used (e.g. in some typewritten documents and postings in Usenet newsgroups).

Abbreviated CBM and cbm in the freight business and MTQ (or numeric code 49) in international trade.

Multiples and submultiples[link]

See 1 E-3 m³ for a comparison with other volumes.

Multiples[link]

Cubic decametre

the volume of a cube of side length one decametre (10 m)

equal to a megalitre

1 dam³ = 1,000 m³ = 1 ML

Cubic hectometre

the volume of a cube of side length one hectometre (100 m)

equal to a gigalitre

1 hm³ = 1,000,000 m³ = 1 GL

Cubic kilometre

the volume of a cube of side length one kilometre (1,000 m)

equal to a teralitre

1 km³ = 1,000,000,000 m³ = 1 TL

Submultiples[link]

Cubic decimetre

the volume of a cube of side length one decimetre (0.1 m)

equal to a litre

1 dm³ = 0.001 m³ = 1 L

Cubic centimetre^[3]

the volume of a cube of side length one centimetre (0.01 m)

equal to a millilitre

1 cm³ = 0.000001 m³ = 10^-6 m³ = 1 mL

Cubic millimetre

the volume of a cube of side length one millimetre (0.001 m)

equal to a microlitre

1 mm³ = 0.000000001 m³ = 10^-9 m³ = 1 µL

Notes[link]

1. ^ From 1901 to 1964 the litre was defined as the volume of one kilogram of pure water at 4°C and 760 millimetres of mercury pressure. During this time, a litre was about 1.000028 dm³. In 1964 the original definition was reverted to.
2. ^ http://www.bipm.org/en/si/si_brochure/chapter4/table6.html
3. ^ The cubic centimetre is the base unit of volume of the CGS system of units. The colloquial abbreviations "cc" and "ccm" are not SI but are common in some contexts such as cooking, engine displacement and medicine.

Look up kilometre or kilometer in Wiktionary, the free dictionary.

The kilometre (American spelling: kilometer; SI symbol: km) is a unit of length in the metric system, equal to one thousand metres (kilo- being the SI prefix for 1000). It is now the measurement unit used officially for expressing distances between geographical places on land in most of the world; notable exceptions are the United States and the United Kingdom where the statute mile is the official unit used.

k (pronounced kay) is occasionally used in some English-speaking countries as an alternative for the word kilometre in everyday writing and speech.^[1][2][3] A slang term for the kilometre in the U.S. military is klick.^[4]

Pronunciation[link]

This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (October 2011)

There are two common pronunciations for the word:

• /ˈkɪlɵmiːtər/ KIL-o-mee-tər and
• /kɨˈlɒmɨtər/ ki-LOM-i-tər

The former pronunciation follows the general pattern in English whereby SI units of measurement are pronounced with the stress on the first syllable, and the pronunciation of the actual base unit does not change irresepective of the prefix. It is generally preferred by the British Broadcasting Corporation (BBC) and the Australian Broadcasting Corporation (ABC).

Many scientists and other users, particularly in countries where the Metric System (SI) is not widely used, use the pronunciation with stress on the second syllable.^[5][6] The latter pronunciation follows the stress pattern used for the names of measuring instruments (such as micrometer, barometer, thermometer, tachometer and speedometer). The problem with this reasoning, however, is that the word meter in those usages refers to a measuring device, not a unit of length. The contrast is even more obvious in countries using the English rather than American spelling of the word metre.

When Australia introduced the metric system in 1975, the first pronunciation was declared official by the government's Metric Conversion Board. However, the Australian Prime Minister at the time, Gough Whitlam, insisted that the second pronunciation was the correct one because of the Greek origins of the two parts of the word.^[7]

Equivalence to other units of length[link]

Units are given to three significant figures:

Visualisation[link]

The kilometre may be visualised in terms of prominent landmarks.

Niagara Falls (1039 m)[link]

Niagara Falls from Prospect Point. The extremity of the Horseshoe Falls in the distance is about one kilometre away The distance between the American extremity of the Niagara Falls and the Canadian extremity is 1039 m,[10] or slightly more than a kilometre. Although the length of the rim of the Canadian extremity (Horseshoe Falls) is quoted as being 790 m and the rim of the American extremity American Falls as being 320 m which add up to more than 1110 m, the rim of the Horseshoe falls is far from straight, so the direct distance between the end-points is 304 m. 43°05′08″N 79°04′08″W / 43.08557°N 79.06885°W / 43.08557; -79.06885 NE extremity of American Falls (Prospect Point) 43°04′44″N 79°04′41″W / 43.07901°N 79.07798°W / 43.07901; -79.07798 SW extremity of the Horseshoe Falls

The Mall, London (987 m)[link]

The Mall from Buckingham Palace on the occasion of the Queen's golden jubilee. The Victoria Memorial is in the foreground and the Admiralty Arch in the distance is about one kilometre away. The Mall, which leads up to Buckingham Palace, is one of London’s main tourist attractions. Immediately in front of the palace is the Victoria Memorial, erected in memory of Queen Victoria (foreground of the picture to the right). At the opposite end is the Admiralty Arch which links The Mall to Trafalgar Square. The distance from the entrance to the Admiralty Arch to the centre of the Victoria Memorial is 987 m.[10] 51°30′07″N 0°08′26″W / 51.50185°N 0.14064°W / 51.50185; -0.14064 Centre of the Victoria Memorial 51°30′24″N 0°07′44″W / 51.50671°N 0.12876°W / 51.50671; -0.12876 Entrance to the Admiralty Arch

Kowloon – Hong Kong Crossing (1007 m)[link]

Hong Kong - Tsim Sha Tsui Pier. The ferry terminal on the Kowloon Peninsular, visible in the centre of the picture, is about a kilometre from the Tsim Sha Tsui Ferry Pier. Hong Kong Harbour boasts one of the busiest waterways in the world. Until 1970 the only way to cross the harbour was the Star Ferry which had terminals on the Kowloon peninsular and the island of Hong Kong itself. The distance that the ferry travels, as measured from passenger entrance to passenger entrance is 1007 m.[10] 22°17′13″N 114°09′41″E / 22.28707°N 114.16133°E / 22.28707; 114.16133 Hong Kong (Central Star Ferry Pier) 22°17′37″N 114°10′05″E / 22.29371°N 114.16803°E / 22.29371; 114.16803 Kowloon (Tsim Sha Tsui Star Ferry Pier)

Central Park, Manhattan, New York City[link]

Central Park in New York City is 849 metres wide. It extends (roughly east and west) from Fifth Avenue to Eighth Avenue (also known as Central Park West). The distance between Eighth Avenue and Madison Avenue (one block east of Fifth Avenue) is 1011 metres. The width of the park is visible from many nearby skyscrapers and is walked daily by many people.

The width of Central Park is visible from many buildings in Manhattan, and the park is walked regularly by many residents and visitors.

Suspension bridges[link]

The Tagus Bridge in Lisbon, Portugal has a central span of 1.013 km A number of suspension bridges have a central span of a kilometre or more. The George Washington Bridge in New York (central span 1067 m) was the first bridge in the world to have a span of more than a kilometre and between 1931 and 1937, had the longest span of any bridge in the world. Other bridges that have a central span of about one kilometre include: 1030 m Third Kurushima-Kaikyo Bridge in Japan 1020 m Second Kurushima-Kaikyo Bridge in Japan 1013 m Ponte 25 de Abril (Tagus Bridge) in Lisbon, Portugal 1006 m Forth Road Bridge in Scotland 990 m Kita Bisan-Seto Bridge (Great Seto Bridge) in Japan 988 m Severn Bridge linking England and Wales

International usage[link]

Chinese expressway distances road sign in eastern Beijing. Although the primary text is in Chinese, the distances use internationally recognised characters.

The United Kingdom and the United States are the only two developed countries which continue to use miles on road signs.^[11]

United Kingdom[link]

In the United Kingdom, road signs show distances in miles^[12][13] and location marker posts that are used for reference purposes by road engineers and emergency services show distance references in unspecified units which are kilometre-based.^[14] The advent of the mobile phone has been instrumental in the British Department for Transport authorising the use of driver location signs to convey the distance reference information of location marker posts to road users should they need to contact the emergency services.

United States[link]

In the US, the National Highway System Designation Act of 1995 prohibits the use of federal-aid highway funds to convert existing signs or purchase new signs with metric units.^[15] The Executive Director of the US Federal Highway Administration, Jeffrey Paniati, wrote in a 2008 memo: "Section 205(c)(2) of the National Highway System (NHS) Designation Act of 1995 prohibited us from requiring any State DOT [Department of Transport] to use the metric system during project development activities. Although the State DOT's had the option of using metric measurements or dual units (metrics/inch-pounds), all of them abandoned metric measurements and reverted to sole use of inch-pound values."^[16] The Manual on Uniform Traffic Control Devices since 2000 is published in both metric and American Customary Units. (See also Metrication in the United States.)

Covering one kilometre[link]

The time taken to cover a kilometre is dependent on one's speed. Walking on flat ground, a hiker can expect to cover one kilometre in 12 minutes^[17] while a car travelling at a speed of 120 kilometres per hour (75 mph) — the speed limit in many European countries — will cover a kilometre in 30 seconds.

Some sporting disciplines feature 1000 m (one kilometre) races in major events (such as the Olympic Games), but in other disciplines, even though world records are catalogued, the one kilometre event remains a minority event. The world records for various sporting disciplines are:

See also[link]

Look up kilometre in Wiktionary, the free dictionary.

• Conversion of units, for comparison with other units of length
• Cubic kilometre
• Orders of magnitude (length)
• SI prefix
• Square kilometre
• 1 kilometre

Notes and references[link]