chains (ch) to Kilometers (km) conversion

What is the chain?

The chain (ch) is a unit of length in the imperial and US customary systems, equal to 66 feet, traditionally used in surveying and land measurement.

Definition

One chain equals 66 feet, or 22 yards, or 4 rods.

$$1\ \text{ch} = 20.1168\ \text{m}$$

There are 80 chains in a mile and 10 square chains in an acre. This value uses the international foot; the US survey chain is larger by a factor of 1200/1199, giving about 20.11684 m.

Origin and History

The chain is named for Gunter's chain, a physical measuring device introduced by the English clergyman and mathematician Edmund Gunter around 1620. It consisted of 100 iron links totalling 66 feet, elegantly bridging the traditional (base-4/16.5) and decimal systems: distances could be recorded in decimal links yet still yield whole numbers of acres and miles. It became the standard tool of English and American surveyors for centuries.

Law and Notable Facts

The chain underpins the US Public Land Survey System, in which section lines and township grids were laid out in chains. A cricket pitch measures exactly one chain (22 yards) between the wickets—a lasting everyday trace of the unit. The chain is now largely obsolete outside historical land records and cricket.

Real-World Examples and Conversions

• A cricket pitch is 1 chain = 22 yards = 66 ft long.
• 1 chain = 100 links = 4 rods = 20.1168 m.
• 80 chains = 1 statute mile.
• An acre is 1 chain by 10 chains (10 square chains).

What is the kilometer?

Kilometers are a commonly used unit for measuring distances. Here's some information about them.

Kilometer Defined

A kilometer (km) is a unit of length in the metric system, equal to 1000 meters. It is widely used around the world for measuring distances between geographical locations, lengths of roads, and athletic distances.

Origin and Formation

The metric system, from which the kilometer is derived, was created in France in the late 18th century. The meter was initially defined as one ten-millionth of the distance from the equator to the North Pole along a meridian. The prefix "kilo-" comes from the Greek word "chilioi," meaning thousand. Therefore, a kilometer is simply one thousand meters.

The relationship between kilometers and meters is:

$1 \text{ km} = 1000 \text{ m}$

Notable Associations

While no specific law or person is uniquely tied to the kilometer itself, the broader development of the metric system involved many scientists and mathematicians of the time. The standardization and adoption of the metric system significantly aided scientific progress and international trade.

Real-World Examples

• Distances between Cities: The distance between New York and Los Angeles is approximately 3,944 kilometers.

• Road Lengths: Highway systems and major roads are often measured and marked in kilometers. The Pan-American Highway, for instance, stretches over 30,000 kilometers.

• Athletic Events: Long-distance running races often involve distances measured in kilometers, such as 5k (5 kilometers), 10k (10 kilometers), and marathons (approximately 42.2 kilometers).

• Geographic Features: The length of rivers, mountain ranges, and other geographical features are commonly described in kilometers. For example, The length of Nile river is approximately 6,650 kilometers.

• Altitude: While altitude is often measured in meters, higher altitudes such as the height of commercial airliners can be specified in kilometers. Commercial airlines usually fly between 9 to 13 kilometers.

Conversions to Other Units

• To miles: $1 \text{ km} \approx 0.621371 \text{ miles}$

• To feet: $1 \text{ km} \approx 3280.84 \text{ feet}$

• To inches: $1 \text{ km} \approx 39370.1 \text{ inches}$