Two-thirds of a cup corresponds to 5.28 ounces. Due to the difficulty of measuring liquids by the ounce, conventional measuring equipment are now labelled with predetermined amounts. However, knowing the conversion rate enables one to more accurately estimate the quantity of a product based on its weight.
Typically, liquid products are packed by the fluid ounce, which differs from the solid ounce. An ounce of honey has a greater mass than an ounce of water. It is vital to keep in mind that liquids are measured by volume as opposed to weight when following recipes that call for a certain weight of an ingredient.