A jigger, also known as a shot glass, is a device used to measure liquor. Jiggers come in different sizes, but the most common size is 1.5 ounces. Most bartenders use jiggers to make cocktails.

When measuring liquor with a jigger, fill the jigger to the top line for a single shot. If you are making a cocktail that calls for two shots of liquor, fill the jigger to the top line and then fill it again to the second …