Convert Square Kilometers to Acres (sq km to acre) ▶
How to convert
1 acre (acre) = 0.00404686 square kilometer (sq km). Acre (acre) is a unit of Area used in Standard system. Square Kilometer (sq km) is a unit of Area used in Metric system.
Acre: A Unit of Area
An acre is a unit of area that is commonly used for measuring land in the United States and the United Kingdom. It is equal to 43,560 square feet, or 4,840 square yards, or about 4,047 square meters, or 0.4047 hectares. The acre is defined as the area of a rectangle that has a length of one chain (66 feet) and a width of one furlong (660 feet). This is equivalent to 10 square chains, or 1/640 of a square mile.
The acre is not a standard unit in the International System of Units (SI), but it is legally recognized in some countries as a supplementary unit that can be used for trade if given as additional information and not used for land registration.
History of the Acre
The word acre comes from the Old English word aecer, which means “field” or “open land”. It is related to the Latin word ager, which also means “field”.
The acre was originally a measure of the amount of land that could be plowed by one man with a team of eight oxen in one day. This varied depending on the soil quality and the type of plow used, but it was generally around 40 rods (660 feet) long and four rods (66 feet) wide.
The acre was used as a common measure of land area in many countries in Europe and the British Isles since the Middle Ages. It was standardized by King Edward I of England in 1305 as 4,840 square yards. However, there were also different regional variants of the acre that ranged from 0.19 to 0.911 hectare.
The acre was brought to North America by the British colonists and became the standard unit of land measurement in the United States and Canada. In 1959, the international yard and pound agreement defined the international yard as exactly 0.9144 meter, which made the international acre exactly 4,046.8564224 square meters. However, the United States decided to keep using the US survey foot (and thus the US survey acre) for some purposes, which differs from the international foot by only four parts per million.
How to Convert Acre to Other Units
To convert an acre to other units of area, we can use the following conversion factors:
To convert from other units to an acre, we can use the inverse of these conversion factors.
For example, to convert 10 hectares to acres, we can use:
10 hectares x (1 acre / 0.4047 hectare) = 24.71 acres
Where Acre is Used
The acre is still widely used in the United States and the United Kingdom for measuring land area, especially for real estate, agriculture, forestry, and environmental planning. It is also used in some other countries that have historical ties with Britain, such as India, Pakistan, Bangladesh, Sri Lanka, Nepal, Jamaica, Ghana, Liberia, and The Bahamas.
Some examples of uses of the acre are:
Example Conversions of Acre to Other Units
Here are some example conversions of an acre to other units:
Square Kilometer: A Unit of Area
Definition of the Square Kilometer
A square kilometer is a unit of area that measures the size of a surface. It is defined as the area of a square whose sides are one kilometer long. A square kilometer is equal to 1,000,000 square meters, 100 hectares, or 0.386102 square miles. It is also the base unit of area in the metric system.
How to Convert Square Kilometer to Other Units
To convert a square kilometer to other units of area, we need to multiply or divide by a conversion factor. A conversion factor is a number that relates two units of measurement. For example, to convert a square kilometer to a square mile, we need to multiply by 0.386102, which is the conversion factor between these two units. Here are some common conversion factors for square kilometer and other units of area:
Where Square Kilometer is Used
The square kilometer is widely used around the world as a standard unit of area measurement. It is used for various purposes, such as measuring the size of countries, regions, cities, lakes, islands, parks, forests, and more. Different countries may have different preferences or regulations for using the square kilometer or other units of area in different applications. Here are some examples:
History of Square Kilometer
The concept of measuring area by using squares dates back to ancient times. The ancient Egyptians, Babylonians, Greeks, and Romans all used different units of area based on squares with different side lengths. For example, the ancient Egyptians used a unit called setat, which was equal to a square with sides of 100 cubits (about 52 meters). The ancient Greeks used a unit called plethron, which was equal to a square with sides of 100 feet (about 30 meters). The ancient Romans used a unit called iugerum, which was equal to a square with sides of 120 feet (about 35 meters).
The modern definition of the square kilometer was established in 1795 by the French Academy of Sciences as part of the metric system. The metric system was designed to create a universal and rational system of measurement based on natural phenomena and decimal multiples. The original definition of the meter was one ten-millionth of the distance from the equator to the North Pole along a meridian. The original definition of the square kilometer was then derived from this definition as the area of a square whose sides are one thousand meters long.
The definition of the meter has been revised several times over the years to improve its accuracy and precision. The current definition of the meter was adopted in 1983 by the General Conference on Weights and Measures as “the length of the path travelled by light in vacuum during a time interval of 1/299792458 second”. The current definition of the square kilometer is then derived from this definition as before.
Example Conversions of Square Kilometer to Other Units
Here are some examples of converting a given area in square kilometers to other units:
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Acres to Hectares
Acres to Square Feet
Acres to Square Kilometers
Acres to Square Meters
Acres to Square Miles
Acres to Square Yards
Square Kilometers to Acres
Square Kilometers to Hectares
Square Kilometers to Square Meters
Square Kilometers to Square Miles
Square Decimeters to Square Feet
Square Decimeters to Square Inches
Square Feet to Square Decimeters
Square Feet to Square Meters
Square Inches to Square Decimeters
Square Inches to Square Millimeters
Square Inches to Square Yards
Square Kilometers to Square Miles
Square Meters to Square Feet
Square Meters to Square Yards
Square Miles to Square Kilometers
Square Millimeters to Square Inches
Square Yards to Square Inches
Square Yards to Square Meters