Kanker is located at . It has an average elevation of 388 metres (1272 feet).
India census, Kanker had a population of 24,486. Males constitute 50% of the population and females 50%. Kanker has an average literacy rate of 77%, higher than the national average of 59.5%: male literacy is 83%, and female literacy is 71%. In Kanker, 12% of the population is under 23 years of age, meaning they are younger than the population aged 23 and above.