Zip Code 48118 is located in the state of Michigan in the Detroit metro area. Zip code 48118 is primarily located in Washtenaw County. The official US Postal Service name for 48118 is CHELSEA, Michigan. Portions of zip code 48118 are contained within or border the city limits of Chelsea, MI, . The area code for zip code 48118 is 734. 48118 can be classified socioeconically as a Middle Class class zipcode in comparison to other zipcodes in Michigan.