Feet (ft) to chains (ch) conversion

What is the foot?

Understanding Feet

The foot is a unit of length in several different systems, including the US Customary Units and the British Imperial System. It's commonly used to measure lengths and distances in everyday contexts.

Definition and History

The foot is defined as exactly 12 inches. One international foot is equal to 0.3048 meters.

$$1 \text{ foot} = 12 \text{ inches} = 0.3048 \text{ meters}$$

Historically, the foot was based on the human foot, but its length varied across different regions and times. The standardization of the foot measurement helped bring uniformity to various applications. Check out this Wikipedia article on Foot for more history.

Notable Associations

While there isn't a specific "law" tied directly to the foot, its consistent use in various fields like construction, sports, and real estate makes it a foundational unit. No specific person is heavily associated with the unit of measurement.

Real-World Examples

• Height: People often measure their height in feet and inches (e.g., 5 feet 10 inches).
• Room Dimensions: Room sizes are frequently described in feet (e.g., 12 feet by 15 feet).
• Sports Fields: Field dimensions in sports like American football (where yards are used) are based on feet (3 feet in one yard).
• Construction: Lumber and building materials are often sold in foot increments.

Conversions

Here are some common conversions involving feet:

• Feet to Inches: Multiply the number of feet by 12.

  $$\text{Inches} = \text{Feet} \times 12$$

• Feet to Meters: Multiply the number of feet by 0.3048.

  $$\text{Meters} = \text{Feet} \times 0.3048$$

• Feet to Yards: Divide the number of feet by 3.

  $$\text{Yards} = \frac{\text{Feet}}{3}$$

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).