Convert cm to inches

センチメートル

定義
A centimeter (symbol: cm) is an SI unit of length equal to one-hundredth of a meter. It’s part of the metric system’s decimal structure, making it easy to scale between units.

起源
Derived from the prefix センチ (ラテン語 センタム, “hundred”), one centimeter is exactly 0.01 meters. The metric system’s prefixes—from キロ (10³) down to ナノ (10⁻⁹)—allow seamless transitions across vast size ranges.

現代の使用
Centimeters are used globally wherever a finer division of the meter is needed: measuring height, small objects, school rulers, and many scientific contexts outside the United States.

インチ

定義
An inch (symbol: in) is a length unit in the Imperial and U.S. customary systems. Since 1959, one inch equals exactly 25.4 mm. Twelve inches make a foot; thirty-six make a yard.

起源
インチ」という言葉はラテン語に由来する。 ウンシア (“one-twelfth”). Early definitions tied an inch to three barleycorns laid end-to-end or to the average width of three thumbs. Later, it was standardized via the international yard.

現代の使用
Inches remain standard in the U.S., Canada, and the U.K. for construction, screen sizes, and other everyday measurements. They also appear in electronics globally, such as TV and smartphone display diagonals.