Price per ounce is a unit rate calculation used often with precious metals such as gold. So, when you are looking to buy gold as an investment, you will typically find the price quotes are related to per-ounce costs. By multiplying the price per ounce by the number of ounces you are buying or selling, you can determine the total amount for the sale. Price per ounce is also used for other objects, such as food.
Mass the object to find the total number of ounces of the object. For example, assume an object weighs 10 oz.
Find the price of the object. In the example, assume the object is selling for $200.
Divide the price of the object by the number of ounces the object weighs. In the example, $200 divided by 10 oz. equals $20 per ounce.