The centiare is a unit of area used in the metric system, and is a synonym for 1 square meter (m2). The abbreviation for centiare is ca. The centiare measurement is used almost exclusively for land measurements, and it is mostly used in countries where Dutch, French, German, Polish, or Portuguese is spoken. Almost all other countries that have adopted the metric system use the term square meter instead. To compare this measurement to two common imperial units of measure, 1 centiare is equal to 1.19 square yards, and 1 acre is equal to 4,046.85 centiares.
The centiare is part of the metric system, a system that uses decimals in expressing units of measurement. The fundamental unit in expressed in factors of 10: 10, 100, and 1,000 and so on. Prefixes are used to form the names of the multipliers. These include deca, hecto, and kilo for ten, hundred, and thousand, and deci, centi, and milli for tenth, hundredth, thousandth. As an example, the meter is the fundamental unit of measure for length, meaning 1 kilometer is equal to 1,000 meters, and 1 millimeter is one thousandth of a meter.
When used for land measurements, the centiare is commonly used together with the metric unit of area called the "are." In this measurement, 1 are is equal to 100 m2. An example of such a land measurement is 10 ares 8 centiares, or 1008 m2. The word centiare literally means "one hundredth of an are." Other common metric units of measure used for land areas are the hectare, also called the hectometer (hm2), which is equal to 10,000 m2; the decameter (dm2), which is equal to 100 m2, and the square kilometer (km2) which is equal to 1,000,000 m2.
The are was the original fundamental unit of area in the metric system, but is not part of International System of Units (SI). The metric system was revamped in 1960, and given this new name. In the European Union, the use of both the are and hectare are limited to the measurement of land.
The first country to make the metric system its official system of measurement was France in 1791. Today, it is used by most countries in the world. The only countries that don't officially use the metric system are the United States, Liberia, and Myanmar (formerly known as Burma).
