Find the answers to common questions about length conversions, inches, millimeters, and other units of measure related to length and distance
What is the definition of "inch"?
The inch (abbreviation: in or ″) is a unit of length in the (British) imperial and the United States customary systems of measurement. It is equal to 1⁄36 yard or 1⁄12 of a foot. Derived from the Roman uncia ("twelfth"), the word inch is also sometimes used to translate similar units in other measurement systems, usually understood as deriving from the width of the human thumb.Standards for the exact length of an inch have varied in the past, but since the adoption of the international yard during the 1950s and 1960s, it has been based on the metric system and defined as exactly 25.4 mm.
What is the definition of "millimeter"?
The millimetre (international spelling as used by the International Bureau of Weights and Measures; SI unit symbol mm) or millimeter (American spelling) is a unit of length in the metric system, equal to one-thousandth of a meter, which is the SI base unit of length. Therefore, there are one thousand millimeters in a meter. There are ten millimeters in a centimeter.
What is the definition of "centimeter"?
A centimetre (international spelling as used by the International Bureau of Weights and Measures; symbol cm) or centimeter (American spelling) is a unit of length in the metric system, equal to one-hundredth of a metre, one 100th of a meter, equivalent to 0.3937 inches. The centimetre was the base unit of length in the now deprecated centimetre–gram–second (CGS) system of units.
1 centimetre = 10 millimetres
= 0.01 metres
= 0.393700787401574803149606299212598425196850 inches
(There are exactly 2.54 centimetres in one inch.)
What is the definition of "decimeter"?
The decimeter (SI symbol dm) is a unit of length in the metric system, equal to one-tenth of a meter (the International System of Units base unit of length), ten centimeters or 3.937 inches.
What is the definition of "meter" (unit)?
The metre (Commonwealth spelling and BIPM spelling) or meter (American spelling) (from the French unit mètre, from the Greek noun μέτρον, "measure") is the base unit of length in the International System of Units (SI). The SI unit symbol is m.
What is the definition of "foot" (unit)?
The foot (pl. feet; abbreviation: ft; symbol: ′, the prime symbol) is a unit of length in the imperial and US customary systems of measurement. Since the International Yard and Pound Agreement of 1959, one foot is defined as 0.3048 meter exactly. In customary and imperial units, the foot comprises 12 inches and three feet compose a yard.
What is the definition of "yard" (unit)?
The yard (abbreviation: yd) is an English unit of length, in both the British imperial and US customary systems of measurement, that comprises 3 feet or 36 inches.Since 1959 it is by international agreement standardized as exactly 0.9144 meters.