Want the Best Grocery Deals? Use This Savings Tool.

Grocery prices today are anything but transparent. The emergence of AI- and data-enabled personalized pricing (where a retailer tailors promotions to individuals or small groups based on personal data) and its more nefarious cousin, surveillance pricing (a form of price personalization in which companies covertly collect and use customers’ personal data to set prices) threatens the very idea of one price for all consumers. In the past year, Consumer Reports has investigated personalized pricing practices at Instacart and Kroger, as well as Uber and Lyft. Recently, the Federal Trade Commission indicated it would require businesses to reveal when and how they personalize prices for their customers, and several states have moved to ban surveillance pricing.

Against this backdrop, calculating savings based on a set price seems almost quaint. But even old-fashioned unit pricing isn’t as straightforward as it could be.

For example, if you’ve shopped for meat or poultry, you’ve seen unit pricing on package labels. It’s standard practice to label those foods that way. So it’s easy to see that the “value pack” of 10 chicken thighs at $2.49 per pound really does give you more for your money than four thighs at $2.99 per pound—even if the bigger package costs more overall. Assuming your budget can handle it, it’s worth paying the higher price for the bigger package, and freezing what you can’t use immediately.

Whether you’ll consistently find unit-price labels elsewhere in a store depends on where you live and the types of stores where you shop. Nine states—Connecticut, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Oregon, Rhode Island, and Vermont, plus Washington, D.C.—mandate unit pricing, according to the National Institute of Standards and Technology. Arkansas, Hawaii, Mississippi, Montana, Nevada, Virginia, West Virginia, plus Puerto Rico and the U.S. Virgin Islands lay out rules for vendors that voluntarily show pricing. 

But many states don’t require the practice or even provide guidelines for retailers that want to do it. Last year, Florida even repealed a law that laid down rules for stores that voluntarily used unit pricing.

“It’s frustrating,” says Chuck Bell, Consumer Reports’ advocacy programs director. “If anything, we should be strengthening state and federal laws to make sure unit prices are routinely and consistently displayed throughout the country, including on e-commerce websites.”

Online grocery retailers like Amazon, Target, Walmart, and the East Coast food purveyor FreshDirect display unit pricing. And we found some unit pricing on the websites of Albertsons, H-E-B, Kroger, and Wegmans, to name a few. 

But even when unit prices are displayed, shoppers may still have to sweat for their savings. In a store, unit prices listed on labels affixed to a shelf edge might be on a different-colored background than the package price, making them easy to see—or not, making them harder to find. It might be in smaller type that’s difficult to read. Online, you can generally count on the unit price being listed in teeny type. 

Some stores make it easy to compare unit prices. On Safeway’s liquid laundry detergent web page, for instance, you’ll see brands like Arm & Hammer, Gain, Persil, and Tide arrayed side by side with their prices and unit prices under each product photo. Whole Foods makes you click through to each product’s page, so you have to toggle between pages to compare unit prices. Trader Joe’s displays no unit price.

If you can take a few more minutes before or while you shop, it’s worth using unit pricing for at least some of your comparisons. Along with your shopping list, have a hand calculator or smartphone open to do the simple math. A smartphone, in fact, makes it easy to combine store sales, store and manufacturer coupons, cash-back grocery apps, and unit pricing information to get the best deals. 

Before making unit-price comparisons, subtract the value of applicable coupons or discounts. Then make the units of measure identical. (If you need a refresher, here’s one: 16 ounces = 1 pound; 16 fluid ounces = 1 pint; 2 pints = 1 quart; 4 quarts = 1 gallon.) So if the store is selling one product per pound and one per ounce, convert the per-pound item to ounces by dividing the number of pounds by 16. 

For the math- or time-challenged, a unit-pricing app can do the heavy lifting. Of several we looked at, the Unit Price Calculator developed by Steve Kideckel in the Apple App Store and by Six By Nine Apps in Google Play Store seemed the most straightforward. In both, you plug in the unit type (weight, volume, etc.) and the unit of measure (ounces, liters, etc.) for the product as shown on the label, along with the price and the number of items you plan to buy. The app then compares the items using the same unit price and gives you the “answer” on which is better.

You can use unit pricing in many departments of your grocery store, though be aware that smaller grocers may be exempt from state unit-pricing laws. Here’s how to use unit pricing in some key aisles:

Cereal appears to be fertile ground for unit-price-based shopping, in part because of varying box sizes. Those comparisons can, in fact, show that the bigger box isn’t always the better bargain. At a CVS near CR’s headquarters in Yonkers, N.Y., the regular price on a 12-ounce box of Post Honey Bunches of Oats Honey Roasted was $4.99, or 41.6 cents per ounce, while an 18-ounce box cost $8.79, or 48.8 cents per ounce. A sale on the smaller box dropped its price to $1.99, making the deal on that honeyed cereal even sweeter.

If you think the packaging of your favorite cereal has changed while the price hasn’t—that is, it’s been subject to “shrinkflation” —you can use unit pricing to confirm your suspicions. “Cereal is the poster child of shrinkflation,” says Dworsky, who tracks the phenomenon on his website MousePrint.org. “Look at the boxes head-on; they appear to be the same size. Turn them sideways, and you see they made the new packages narrower. Or the new box is taller, but it’s narrower.” By dividing the price by the net weight, you can really see the difference.

Pasta sauce and other jarred products are also ripe for unit-price comparisons. Though it’s common to see manufactured pasta sauce in standard 24-ounce jars, we’ve also seen it in 24.5, 23.9, 22-, 21.5, 16-, 15.5, 15-, and 14-ounce containers. Comparing their prices per ounce cuts your decision-making down to size and can save you money. 

Unit pricing can be useful here, but it can also be tricky because items may be priced individually or as a package. In that case, you can use other comparison tricks. If, say, you wanted to compare the value of a bag of 11 Granny Smith apples at $3.99 with that of individual Granny Smiths at 75 cents apiece, you could simply divide the price of the bag of apples by the number of apples in it. In this case, $3.99 divided by 11 is 36 cents per apple. So the apples in the bag are a better price.

Nabbing a lower unit price of fresh food can also be dicey when it requires you to buy in bulk. If that lower unit price makes you stock up on quantities you can’t store—or that may expire before they’re used—it’s not a deal at all. “If it goes to waste, you’re paying more per unit,”  says Andrea Woroch, an author and speaker in California who focuses on shopping and budgeting. 

For that reason, she recommends being cautious when buying in bulk—regardless of unit price—especially at warehouse stores. “Bulk containers will cost more, so your overall cart total costs more than you normally would spend,” she says. “And if you’re buying with a credit card and don’t pay it all on time, you’ll owe interest, defeating the savings you were after.”

Jars of these kitchen miracles can look the same but hold quite different amounts, so a unit-price app is a must in this aisle. At that Acme in Greenburgh, N.Y., for instance, we found two jars of cumin that appeared to be the same size, one costing $4.89 and the other, $4.99. But the cheaper one had a unit price of $52.59 per pound, while the other was $44.56 per pound. We then took a closer look at the net weights on the labels. The jar that cost more by 10 cents, or 2 percent, held 20 percent more cumin. That could mean a couple more tasty meals without having to run out for a refill.

 “Mega,” “super mega,” “mega plus,” “family mega XL,” “long lasting,” “jumbo,” “forever,” and other hyperboles dance across the package labels of this cushy tushy product. Because of its many variables, toilet paper is hard to compare across brands. A package may tell you the number of sheets per roll and whether the paper is one-ply or two. But it won’t necessarily tell you how big those sheets are (some may be larger than others). And “softer” or more absorbent rolls may look big but have fewer sheets. “Toilet paper is the nemesis of unit pricing,” Bell says.

If you’re determined to figure this out, you can calculate which brand gives you the most surface area—hopefully a comfortable surface area—for your money. Take the square feet per roll stated on the package and multiply it by the number of rolls per package; that’s your total square feet per package. Then take the package price and divide it by the total square feet per package. Create that same unit price for the other brands you’re considering, and compare.

Charmin, Cottonelle, Scott, and Seventh Generation are among the brands that show square feet per roll on their labels, so you can do that comparison with them. 

To save yourself that work—and add the variable of quality—try the free Toilet Paper Value Calculator Pro developed by Albert Wiersch, who goes by TidalWaveOne. The tool not only lets you compare toilet paper packages by price per sheet—including discounts and promotions —but also lets you factor  in the perceived quality of the toilet paper brands on a scale of 0 to 5.  (Check our reviews of seven major brands for our take on quality.) 

Note that the tool bases its calculations on two-ply sheets, a good baseline for most consumers, assuming their septic systems can handle it. To be sure, you’ll get more sheets for your money with one ply. But as Bell says, “For that kind of product, people know what they want. They’re not going to skimp on the ply to save money.”