The move to smaller units (e.g. millilitre vs fluid ounce, gram vs ounce) allows manufacturers to move sizes of packaging up and down with more precision using whole numbers. For example, a 2-ounce bag of chips may be altered to 50 grams, then to 45 grams. Likewise, a variety of packaging sizes may arise, such as 690 grams (about 24 oz) or 1200 grams (about 42 oz), resulting from conversion and rounding of customary units. However, the precise adjustment of packaging sizes is also possible using customary units, e.g. the 2-ounce bag can be downsized to 1.8 and 1.6 ounces as well.
