π Unit Price Calculator
Compare pack sizes and find the real cheapest option.
Best Value
How to Use This Calculator
Enter each product's price, quantity, and unit, and the calculator normalizes everything to a per-unit price so pack sizes can be compared fairly.
Add a row for each pack size you are comparing. Name them so you can tell them apart.
Enter the price and the package quantity, then pick the unit (oz, lb, g, fl oz, count, and more).
Read the unit prices. The cheapest per unit gets the best-value badge, with the savings versus the worst option shown.
Compare within the same dimension: weight with weight, volume with volume, count with count.
How Unit Price Math Works
Unit price is just division, but the units have to match first. A 24 oz jar at $5.99 costs $0.2496 per ounce; a 16 oz jar at $4.29 costs $0.2681 per ounce, so the bigger jar wins. Mixing units is the classic trap: $0.25 per ounce versus $3.99 per pound looks close until you convert and find $3.99 per pound is only $0.249 per ounce. This calculator does the normalization for you across ounces, pounds, grams, kilograms, fluid ounces, milliliters, liters, and plain counts.
Worked Example: Shrinkflation Check
Your usual coffee was 16 oz for $9.99: $0.624 per ounce. The new bag is 12 oz for $9.99: $0.833 per ounce, a 33 percent price hike hiding behind the same sticker price. A competitor sells 2 lb (32 oz) for $18.99: $0.593 per ounce, genuinely cheaper than your old bag. Without unit math, the $9.99 bag feels like the same deal it always was.
Where This Comes Up
Grocery runs are the obvious case, but unit pricing applies anywhere quantity varies: paper goods (per sheet or per roll), cleaning supplies (per fluid ounce), pet food (per pound), diapers (per diaper), and even warehouse clubs where the "bulk deal" sometimes loses to the regular grocery pack. The habit to build is simple: whenever two pack sizes compete, divide before you decide. Over a year of groceries, consistently picking the cheaper unit price on staples can save a typical household several hundred dollars.
Frequently Asked Questions
Why is the bigger pack not always cheaper?
Because manufacturers price pack sizes strategically. The large pack is usually cheaper per unit, but not always: brands sometimes price the mid-size pack as the value option, or shrink the large pack (shrinkflation) while keeping the price. Comparing unit prices is the only way to know for sure.
What is shrinkflation?
Shrinkflation is when a product gets smaller but the price stays the same: a 16 oz bag of chips becomes 14 oz, a half-gallon of ice cream becomes 1.5 quarts. The unit price goes up even though the sticker price does not. Unit-price math exposes it instantly.
How do I read unit price labels?
US store shelf labels show the unit price next to the total price, usually per ounce, per pound, or per 100 count. Compare the unit prices, not the package prices. Watch that both labels use the same unit: per-ounce versus per-pound labels cannot be compared directly without converting.
Which states require unit pricing?
About 16 US states and some cities require unit-price labels on grocery shelves, including New York, Massachusetts, Connecticut, and Rhode Island. Everywhere else it is voluntary, which is why having your own calculator matters.
Should I compare by weight or by count?
Compare by whatever you actually consume. For paper towels, price per sheet or per roll matters more than price per ounce. For cereal, price per ounce. Pick the unit that matches how you use the product, and compare like with like.