Cost driver

Cost driver is a variable, such as the level of activity or volume, that causally affects costs over a given time span.

Definitions

According to Cost Accounting by Horngren, Datar, Rajan (14th edition),

Cost driver. A variable, such as the level of activity or volume, that causally affects costs over a given time span.

According to Managerial Accounting by Braun, Tietz (5th edition),

Cost driver. The primary factor that causes a cost.