Unit price is an important way of comparing the effective cost of different package sizes. Generally speaking, the lower the unit price, the better the deal, and larger packages...

Unit price is an important way of comparing the effective cost of different package sizes. Generally speaking, the
lower the unit price, the better the deal, and larger packages usually offer a better unit price. Savvy shoppers know that the main exception to this rule is when certain package sizes go on sale. Very often in those cases it will be a better deal to buy the sale item, even if a larger package is avaiable.
However, the rules get turned around when coupons come into play. Very often the smallest packages, which had the worst unit price to start with, end up with the BEST unit price after deducting a coupon. If you have multiple coupons, or don't need to buy as much of the item at one time, you'll save more in the long run this way.
Unfortunately while stores generally provide the unit price right on the shelf tag, they don't give you this information for factoring in coupons, so you have to do it yourself. Don't worry, it's easy to do with a calculator (your phone might even have one) or a piece of paper, or even in your head!
