The kilometer marker for any object is its position on a defined route, such as a highway or a road, which is measured in kilometers. It is often expressed with a few decimal places for greater precision.

The number expresses distance-based position along the defined route. Decimal places allow a location between whole-kilometer positions to be described.

The value is a route reference for the object, rather than necessarily a count or identity of a physical roadside sign. A mileage marker expresses the corresponding kind of position in miles.