A yardstick is a straightedge used to physically measure lengths of up to a yard (0.9144 metres or three feet) high. Yardsticks are flat wooden boards with markings at regular intervals.
In countries in which the metric system is used (such as Canada and France), yardsticks bearing imperial units markings on one side (three feet with inch and fractional inch) and metric units on the other (one meter with 100 centimetres and 1000 millimetres) are common, and are sometimes referred to as "metre-sticks" or "metre rules". Sometimes the imperial units are not included. The folding carpenters' rulers used in Scandinavia are usually equipped with double measurements, metrical and imperial on both sides, also functioning as a handy conversion table, accounting for its Scandinavian term: Tommestokk/tumstock (thumb (inch) stick), a term with the same meaning that is also used in Dutch: duimstok. Source