How Do You Calculate Sales Tax on a Used Car Purchase in California?

To calculate the sales tax on a used car purchase in California, add the statewide rate of 7.5 percent to the tax rate of the vehicle's district, states the California State Board of Equalization. The rates range from about 0.10 percent to about 2 percent per district, as of 2015.

California has special jurisdictions, called districts, that collect taxes from sales transactions. Some areas collect more than one district tax, while others do not impose a district tax, notes the California State Board of Equalization. If you have an exact address for a vehicle, the Board of Equalization provides a tool that determines the current applicable sales tax rate for the specific address. The Local Revenue and Allocation Unit is available to answer questions during normal business hours.