How it's calculated
unit price = price ÷ size
price = pack price, size = pack quantity (oz or fl oz). The lower unit price is the better buy; savings % = (higher − lower) ÷ higher.
Common questions
Is the bigger package always cheaper per ounce?
Not always. Bulk sizes usually win, but promotions on smaller sizes can flip the result, which is exactly why comparing per ounce helps.
What is the difference between weight and fluid ounces?
Weight ounces measure mass for solids, while fluid ounces measure volume for liquids. Use the matching one or your comparison will be off.