The municipality covers an area of 44.85 square kilometres (17.32 sq mi).
Of the total population of 5,140, 2,591 are male, 2,248 are female, and 301 are of indeterminate status (Dec 31, 2003).
The population density of the community is 115 inhabitants per square kilometre (300/sq mi).
Districts (villages) of the municipality Affing: Affing with Iglbach, Anwalting, Aulzhausen, Bergen, Frechholzhausen, Gebenhofen, Haunswies, Katzenthal, Miedering, Mühlhausen, Pfaffenzell.
In May 2015 a tornado devastated Affing, causing severe damage.[3]