The short answer: it depends. First and foremost, it depends on when it was built. Older appliances are built better than newer appliances by far. The brand you have also plays a large role, as well as the model series within each brand. It also depends on whether its used by more people versus less, and how well it is maintained. Any broken parts, mechanical or cosmetic, can diminish efficiency, and thereby shorten useful life. Also, don’t expect a new fridge under $500 to last beyond the one year warranty.