While most people think of earbuds as one-size-fits-all, the reality is that they come in a variety of sizes to accommodate different ear shapes and sizes. The smallest size is typically designed for children or people with very small ears, while the largest size is usually reserved for adults with larger ears. There are also a few companies that offer adjustable earbuds, which allow you to customize the fit to your unique ear size. In general, however, most earbuds will fall into one of three main size categories.