Expert shares 8 ways to save money at the supermarket using unit pricing

Unit pricing makes it easier to compare the products on what they cost per unit of measure – for example per 100g or 100ml. When it’s there on the price tag, unit pricing lets you compare what’s the best value regardless of package size, brand or special pricing.  

Ian lives in Queensland, but even once Australia introduced mandatory unit pricing in 2009, he kept fighting for the same rules to apply in New Zealand. At the end of next month, it will finally be against the law for our large supermarkets to not show unit prices in their stores. We’ll have to wait another year for these unit price rules to apply to supermarkets’ websites, though.   

We asked Ian for his tips on using unit pricing – what he calls the “grocery shopper’s best friend” – to save money. Here’s what he shared.  

1. Check if specials are actually a good deal  

Rather than assuming a product that’s on special is great value, we can use unit pricing to compare it to others and decide for ourselves if it’s a better buy.  

2. Compare the bulk bins with what’s on the shelf 

If you usually buy from the bulk section, check if you could be getting it cheaper in a packet from the shelf and vice versa. 

3. Consider comparing fresh and frozen  

Without unit prices, we make assumptions when choosing food. For example, you might be in the habit of buying fresh green beans. However, if you compare fresh with frozen, you could get more beans for the same price.

4. Decide if convenience is worth it  

There are some products we buy because they save us time, but with unit pricing we can check how much we’re paying for the added convenience. For example, if you’re buying grated cheese, compare the unit price with that of a block of cheese and see how much extra you might be paying to not grate your own.

5. Sort by unit price when shopping online  

If you buy your groceries online at Woolworths, you can sort products by “unit price low to high”. So, if you search for breakfast cereal and then use the sort function, it will order the cereals from the cheapest unit price to the most expensive unit price. At the moment, Woolworths Cereal Wheat Biscuits are the best value at $0.55/100g.   

Unfortunately, you cannot do this online for New World or Pak’nSave.  And Ian says it can be unreliable if the supermarket is using different units of measure throughout a category – such as per 100ml for some products and per litre for others.

6. Compare across supermarkets  

While it won’t be compulsory for supermarkets to have their unit pricing sorted online until August 2025, it is already available on some products. If you’re looking at a product instore and wondering if it could be cheaper at the supermarket around the corner, pull out your phone and have a quick look on the competitor’s website. “Unit prices can vary greatly between retailers,” Ian says.

7. Be prepared to still do some maths yourself  

Ian says that even when unit pricing is mandatory, it’s not always going to be easy to compare products using the same unit of measurement. For example, if you’re trying to work out whether to buy liquid, powder or capsule laundry detergent, you will want to compare the cost per wash, which won’t be available on the price tag. Instead, you’ll need to check the packaging to see if it has the recommended amount of washes you can do and then divide the cost of the product by that.  

8. Complain if the unit price isn’t there or difficult to use

Ian says we can make a collective difference by speaking up if we notice a unit price is missing or difficult to use. If supermarkets know we’re watching, they’ll be more likely to stick to the rules. He says if we notice it’s a habit for a supermarket to not display some unit prices once it becomes mandatory on August 31, or unit prices are difficult to use, we should complain to the Commerce Commission.   

Ian has helped consumer organisations in several countries, including New Zealand, to advocate for effective unit pricing. He also represented Consumers International, the global voice of consumers, on an International Standards Organisation project that developed a standard for the provision of effective unit pricing.