## Measurement unit: inches

**Full name:** inch

**Plural form:** inches

**Symbol:** in

**Category type:** length

**Scale factor:** 0.0254

## SI unit: metre

The SI base unit for length is the metre.

1 metre is equal to 39.370078740157 inches.

Valid units must be of the **length** type.

You can use this form to select from known units:

## Definition: Inch

An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot. The inch is usually the universal unit of measurement in the United States, and is widely used in the United Kingdom, and Canada, despite the introduction of metric to the latter two in the 1960s and 1970s, respectively. The inch is still commonly used informally, although somewhat less, in other Commonwealth nations such as Australia; an example being the long standing tradition of measuring the height of newborn children in inches rather than centimetres. The international inch is defined to be equal to 25.4 millimeters.

## Sample conversions: inches