You can calculate your car's value by using websites such as Autotrader and Kelley Blue Book. Each site prompts you for specific information about your car's make, model and condition to provide an estimate of its value.
To use Autotrader's site, navigate to the Value a Car page and select Sell a Car. You must then provide the car's year, make, model, mileage and trim. The site also asks for your ZIP code and email address, though providing an email address remains optional. After you enter the information and select Get Car Values, the site provides approximate values for your car based on its overall condition, ranging from excellent to fair. It also allows you to enter your own asking price and to advertise your car on the Autotrader site.
The Kelley Blue Book site offers a similar setup, asking for your car's year, make, model and mileage on its Car Values page. After you enter this information and click Next, it prompts you to enter your ZIP code to provide value information specific to your location. The site then asks for additional information about the car's equipment, color and accessories. After selecting everything relevant and clicking See Bluebook value, the site asks whether you are likely to sell it to an individual privately or trade it to a dealer. Finally, it prompts you to select the condition of your car and to click the Get Blue Book Value to receive a price estimate.