Two packages of the same food can look very different in price, but the sticker price alone does not tell you which one is the better deal. The unit price does.
What is a unit price?
A unit price is the cost per standard amount, such as per 100 grams, per kilogram, per litre, or per 100 millilitres. It lets you compare products that come in different sizes on equal terms.
You can usually find it on the shelf tag, in smaller print near the main price.
A simple example
Say one box of pasta costs $2.50 for 500 grams and another costs $3.60 for 900 grams.
- The first is $2.50 divided by 5, which is $0.50 per 100 grams.
- The second is $3.60 divided by 9, which is $0.40 per 100 grams.
The larger box costs more up front but is cheaper per gram.
When bigger is not cheaper
People often assume the bigger package is the better deal, but that is not always true. Sales, store brands, and package shapes can change the math. Always check the unit price before you decide.
Watch for these traps
- Different units on the shelf. One tag might show price per 100 g and the next price per kg. Make sure you are comparing the same unit.
- Sale tags that hide the unit price. Check the small print rather than only the big sale number.
- Shrinking packages. The same package size can hold less than before, so the same price may now mean a higher unit price.
- Multi-buy deals. "2 for $5" is only a deal if the unit price beats your usual option, and you will actually use both.
When the cheapest unit price is not the best choice
A low unit price only helps if you use the food. A huge bag of something that goes stale before you finish it is no bargain. For perishable items, buy the size your family will actually eat.
Quick checklist
- Find the unit price on the shelf tag.
- Make sure you are comparing the same unit.
- Pick the lowest unit price you will actually use.
- For non-perishables, consider stocking up when the price is low.
The bottom line
Unit pricing is one of the simplest ways to save without giving up anything. GopherCart compares prices gram for gram, so you can see the true cost across stores without doing the math yourself. Always check the shelf price at checkout.