What Is an Inch?
An inch (symbol: in or ″) is a unit of length in the imperial and United States customary systems of measurement. It is defined as exactly 2.54 centimeters.
Definition
1 inch = 2.54 cm = 25.4 mm = 1/12 foot = 1/36 yard
History
The inch dates back to at least the 7th century. The word comes from the Latin “uncia” meaning “one twelfth.” It was standardized internationally in 1959 as exactly 25.4 mm.
Common Uses
- Screen sizes (TVs, monitors, phones)
- Paper sizes in the US
- Construction and carpentry
- Tire sizes
- Pipe diameters
Relation to Other Units
- 1 inch = 2.54 cm
- 12 inches = 1 foot
- 36 inches = 1 yard
- 1 inch = 25.4 mm