If taken well care of and not affected by one of the many design f***ups that Apple is so notoriously infamous for an iMac can last quite a while. My neighbor is still rocking a 2010 iMac while her teenage daughter has just inherited her slightly oder 2007 iMac. Both are in great working condition and have been upgraded over the years, the 2010 with extra RAM and a 128GB SSD and the 2007 with extra RAM.