How many people died in nazi concetration camps?

The biggest camps had about 16,000 inmates at any one time. As people were worked to death they were replaced by new arrivals. At the extermination camps, such as Treblinka II and the Birkenau section of Auschwitz, most newly arrived Jews were gassed as quickly as possible after arrival. From about mid to late 1944 onwards many prisoners were moved from the camps in Poland to camps in Germany itself, which then experienced a huge increase in numbers.