CM ⇄ Inches Converter
Centimeter
Definition:
A centimeter (cm) is a unit of length commonly used for measuring small distances or dimensions. It is part of the International System of Units (SI), which is the modern form of the metric system. A centimeter is precisely defined as one-hundredth of a meter, making it a standardized and widely accepted unit of measurement.
History/origin:
The centimeter comes from the metric system, which is built on the SI standard. It is a unit of length equal to one hundredth of a meter, as shown by the centi prefix. The base unit, the meter, has no prefix and a factor of 1 in this decimal structure.
This system uses different prefixes to represent various factors of ten. Common units include kilo, mega, giga, tera, milli, micro, and nano. Understanding these helps in easily navigating between metric units in daily measurements.
Current use:
The centimeter, a smaller denomination of the meter, is used in many applications worldwide, especially in countries that follow metrication. In several instances, height is commonly measured in centimeters, unlike in the United States. This unit helps provide precise measurements where the full meter is too large. Its use is widespread and practical across different regions.
Inch
Definition:
The inch (symbol: in) is a unit of length used in the imperial and US customary systems of measurement. It was standardized in 1959 to equal exactly 25.4 millimeters. There are 12 inches in a foot and 36 inches in a yard.
History/origin:
The inch comes from the Latin word uncia, meaning one-twelfth of a Roman foot. It was one of the earliest units used for measuring length, and its definition has changed over time. The earliest way people defined an inch was with barleycorns—three dry, round grains of barley placed end-to-end. Another method was by using the width of a human thumb, taking the averaging size of three thumbs: small, medium, and large.
Over the years, many standards were used until the modern definition was agreed upon, which is now based on the international yard.
Current use:
Today, the inch is widely used in the United States, Canada, and the United Kingdom for everyday measurements. It’s also commonly seen in Japan and other countries, especially when talking about electronic parts like the size of display screens. Whether you’re shopping for a TV or a phone, the screen size is usually shown in inches.