Quite simply, it depends on two important factors. First and foremost, it depends on when it was built. Older appliances are built better than newer appliances by far, since manufacturers designed them to last. Second, the brand you have also plays a large role, and to some extent, the model series within each brand. Other contributing factors include: how many users; how well it is maintained, i.e. vacuum condenser or cleaning spills. Any broken parts, mechanical or cosmetic, can diminish efficiency, and thereby shorten useful life. Also, not all refrigerators and freezers are made equal. Don’t expect a cheap $500 fridge to last much beyond the one year warranty.