How Long Do Microwaves Last? A Guide to Maximizing Your Appliance’s Lifespan. Have you ever wondered how long your trusty microwave will last? Microwaves have become a staple in modern kitchens, making our lives so much easier. But just like any other appliance, they do have a limited lifespan. In this article, we’ll delve into the factors that affect how long microwaves typically last and share some practical tips to help you maximize their lifespan. So, let’s get started! Understanding Microwave Lifespan: Microwave lifespans can vary depending on several factors.