Most automotive repair shops charge a flat hourly rate for labor, and the amount of hours the shop charges depends on the type of repair. The price for replacement parts is a separate charge the shop adds to the total cost.
Owners and shop managers determine their hourly rate by accounting for the price of tools, shop overhead and competitor's rates. Shop managers use labor manuals to determine the amount of time to charge for a repair. Examples of these types of repair manuals include Chilton Professional and Real-Time Labor Guide, as of 2015.
Some shops also charge a separate diagnostic fee. The fee covers any work the technicians do to determine the problem with the vehicle.