Pennfield Charter Township is a charter township of Calhoun County in the U.S. state of Michigan. It is part of the Battle Creek, Michigan Metropolitan Statistical Area. The population was 8,913 at the 2000 census.There were 3,532 households out of which 31.5% had children under the age of 18 living with them, 56.9% were married couples living together, 9.4% had a female householder with no husband present, and 30.1% were non-families. 25.5% of all households were made up of individuals and 9.1% had someone living alone who was 65 years of age or older. The average household size was 2.52 and the average family size was 3.01.