The two main camps, Auschwitz and Birkenau, are about 2.5km (1 1/2 miles) apart. It takes about 30 minutes to walk from one to the other. Alternatively, the museum runs free shuttle buses between the two camps. The timetable is posted at the stop outside the main entrance; the buses run about once an hour in both directions (less frequently in winter). A cab ride between the two camps will cost you about 15 z.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.