Selecting the right enamel mug involves considering both its size and how much it holds. A common enamel mug is around between 3 and 4 inches in diameter, with a height that can vary from 4 to 6 inches. When it comes to capacity, most enamel mugs hold between 10 and 16 ounces of liquid. To best choose an enamel mug, consider how you'll be using it