How to Read Unit Prices and Never Overpay for Groceries
Unit pricing is the single most powerful tool for saving money at the grocery store. Here's how to use it.
You're standing in the cereal aisle. The 500g box costs $4.99 and the 750g box costs $6.99. Which is the better deal?
Most people grab the cheaper box. But the unit price tells a different story.
What Is Unit Price?
Unit price is the cost per standard unit of measurement -- per 100g, per litre, per kilogram. It strips away package size so you can compare any two products on equal footing.
| Box | Sticker Price | Unit Price (per 100g) |
|---|---|---|
| 500g | $4.99 | $1.00 |
| 750g | $6.99 | $0.93 |
The larger box costs more at checkout but is 7% cheaper per serving. Over a year of cereal, that adds up.
7%
cheaper per serving for the larger box
Where to Find It
In Quebec, stores are required to display unit pricing on shelf labels. Look for the small text below the sticker price that says "price per 100g" or "price per litre."
Pro Tip
The unit price on the shelf label is often in a smaller font and positioned at the bottom or side of the price tag. Train your eyes to look there first before looking at the big number.
When Unit Price Tricks You
Unit pricing isn't always straightforward. Watch out for:
1. Different Units
Sometimes one product shows price per 100g and another shows price per unit. You can't compare these directly. Do the math yourself or use a tool like Kaso that normalizes everything.
2. Perishable Waste
A 2kg bag of apples at $0.80/100g is only a better deal than loose apples at $0.90/100g if you actually eat all 2kg before they go bad. Factor in waste.
3. Sale-Stacking Illusions
A product on "sale" might still have a worse unit price than a competitor's regular price. The discount percentage means nothing without comparing the final unit price.
| Product | Store A (on sale) | Store B (regular) |
|---|---|---|
| Olive Oil (750ml) | $8.99 | $7.49 |
| Per 100ml | $1.20 | $1.00 |
A 'sale' at Store A is still more expensive than Store B's regular price.
The 5-Second Unit Price Check
Next time you're shopping, try this:
- Look at the shelf label, not the product
- Find the unit price (per 100g or per litre)
- Compare across brands in the same category
- Ignore the sticker price -- it's designed to distract you
This one habit can save you 10-15% on your grocery bill without changing what you buy.
10-15%
potential savings from unit price checking
How Kaso Uses Unit Pricing
When you browse deals on Kaso, our Value Score already factors in unit pricing. A product with a great sticker price but poor unit value gets a lower score. You don't have to do the math -- we do it for you.
The next time someone asks you whether the big box or the small box is a better deal, you'll know exactly where to look.
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Compare prices across Metro, Maxi, Super C, IGA and more with Kaso's Value Score.
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