The document provides comparisons for common units of measurement including millimeters, centimeters, meters, kilometers, milliliters, liters, grams, kilograms, inches, feet, yards, and miles to help describe their relative sizes. For example, it notes that a millimeter is about the width of a pin, a meter is about the width of one and a half doors, a liter is half the size of a large pop bottle, and a mile is four times around a track.