How easy is it to use unit pricing in the supermarket?

I was involved in the campaign that resulted in large supermarkets having to show on shelf labels the unit price (price per unit of measure) pre-packaged products. So I’m interested in the Community’s views on how easy it is to use unit pricing to compare value for money when buying groceries (especially pre-packaged items) on-line.

To me, for a variety of reasons, it seems much easier to use unit pricing when buying pre-packaged groceries in bricks and mortar stores than online. I’ll not give my reasons just now so that I do not influence any responses.
However, I do think that the following paragraph from the Roy Morgan report is very relevant to on-line shopping for groceries and to my specific interest in the ability to use unit pricing effectively.

“One of the great things about online shopping in general is its convenience, but when it comes to groceries, this isn’t necessarily the case. What with all the scrolling, searching for products by key words rather than spotting them on the shelves, being organised enough so you know exactly what you want rather than grabbing items as you see them, it can be quite a challenge!

I am trying to get academic researchers interested in this issue and any ideas, experiences, etc would be a great help.

Ian Jarratt


Unit pricing is a great help, but it is made harder by inconsistency. A supermarket may have one container of a product priced /100g, the next one with a similar/same product at /kg, and the next one priced on a /ml basis. There can be inconsistencies within brands as well as across brands.

It’s not to hard to work out the /100g vs the /kg cost comparison, or the /litre vs ml comparison, but it is impossible to work out which is the better deal when comparing $/weight against $/volume of a similar or same product.


Unit pricing’s great, but it should be displayed in a size equal to the total price of the item.


The one that threw me was tea bags. I was after some green tea one day and did the comparison between each of the brands. The UOM in this case was per tea bag so I grabbed the cheapest one. However I later found out that the ones that I bought had less tea in the bag than some of the others. So in hindsight the UOM should realistically be by weight and not per bag.

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Colour me confused about that one. Isn’t the price for the total size of the item, so that is clearly shown? :smiley:

Did you mean like the difference between showing litres per dollar or dollars per litre?

Apologies for any confusion. In my experience, the unit pricing (e.g. $ per kg or $ per litre) is always displayed in a smaller size than the total price of the item (e.g. $4.79). I believe that the two things should be displayed in the same size print. I hope that clarifies it.


Yes, the use of inconsistent units of measure to show the unit price for different packs of the same or similar products is a real problem for consumers that needs fixing. In addition to your examples there is also the problem of some being unit priced by weight and some per each. By the way, fixed measure packaged products (such as meat, fish, cheese, nuts and F&V) are unit priced per kg, not per 100g, to be consistent with how they are unit priced when sold loose or in random measure packs.


I share your concern about the small print size most retailers use to show the unit price on shelf labels and other in store signs. This greatly reduces consumer awareness and use of unit pricing. In some US states the unit price must be the same, or a very similar, size as size as the selling price. But to reduce any confusion with the selling price, the unit price also has to be on a specific coloured background and accompanied by the words “unit price”.


As I mentioned in my reply to meltam6554, this is a substantial problem with many products. It can also prevent comparison between similar products eg tea bags and loose tea, and fruit and veg sold either per piece or by weight. Unfortunately, we still do not know much about what consumers prefer even for your example of tea bags. Some would argue that tea bags are different to loose tea and it is more important to help have a unit of measure that helps consumers to compare tea bags. Showing the unit price per bag might make it easier for consumers to do this and if they want to they can take into account separately any weight and other differences.


I was relating my frustration based on my observations on unit pricing. What should be done, eg consistent unit pricing per kg, is obviously not complied with.

As for the tea bag question raised by @fred, I would want to see unit pricing by weight, regardless of packaging. The reason for this is inconsistency in the contents of the teabags. What I can see happening if it were by the number of bags is some manufacturers reducing the amount of tea per bag to save costs. This would be comparable to the shrinkage we have seen in confectionary.

In my opinion, the unit price must reflect some immutable consistent measure that can’t be manipulated by manufacturers/packagers.

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The tea bag is a perfect example of the problem a law would need to address, and it is not always clear cut. A consumer is certainly reasonably interested in the price per tea bag, which s/he accepts as a proxy for a single cuppa (and of the strength that consumer wants which is a variable in itself). Vendor 1 could have more tea per bag than vendor 2, but would vendor 1’s bags make more cups of tea (of “the strength”) in a practical sense, as packaged? If each bag had a multiple of the tea weight, yes, otherwise probably not and the bag would be thrown in the garbage after one use. Those who like weak tea would use and evaluate bags differently than those who prefer strong tea, but the cost per cup is still relevant.

To resolve that the unit pricing would need to include both price per bag and tea per bag, not unit weight cost of the tea. (Unit weight cost of the tea is economically interesting but in a practical sense is it meaningful for the purchase of tea bags to make cups of tea?)


In a similar vein, I believe that there should be standardised package sizes for similar products. Coles branded quick oats are in a 900 g package. Woolworths are in a 750 g package. IGA used to be in a 1 kg package for about the same price (then $1.20) as the Coles 900 g, but in the name of price-matching now sell a smaller package at a higher price. It was a while ago, so I haven’t bought it from IGA since.

While that could make price comparisons easier it does not suit everyone as we all use different quantities vs spoilage/waste, and I doubt it would fly if only because the American market is so dominant, stubbornly welded onto their “Standard” units of measure although stumbling forward, while the rest of the world has long ago moved on to metric. (It affects supply chain packaging and machinery.)

Importers could push for exemptions for imports, or a standardised 226.8g (8 oz in America); many American companies are adopting curious “Standard unit” sizes as 47.3oz (1.4L) as they go metric, while we may be more comfortable with just 1 or 2L.

Take olive oil. Common sizes are 100ml, 250ml, 500ml, 750ml, 3L and 4L. Which is mandated? If all, what improved? I trust you can see where this would go once all the vested interests and the practical needs of individual consumers meet to define a well intentioned model.

Now you know why I need ideas on, and help, with this!

It is complex and involves consideration of what is best for consumers, what manufacturers are required to provide on packs, and what retailers can provide on shelf labels etc.

And, the situation varies greatly between products. I agree that one of the benefits of unit pricing by weight/volume etc rather than by count is that it helps consumers (if they remember unit prices) to spot downsizing.

But for example with tea bags if consumers mainly think of quantity in terms of number of bags showing the unit price per 100g of tea might not be helpful.

However, it might be very helpful to show the unit price per unit of weight for products sold in individual sachets within a pack and in a single pack from which you remove the required amount, for example chocolate drink powder.

And, then there’s the question of products that do the same job (for example laundry detergents) but which are sold in different forms (weight, volume and tablet) and have different concentrations. If there was reliable and enforced standard for a “wash load” it might be more helpful for consumers to have the unit price per “wash load”.

Any views?

I’m not sure that standardised pack sizes are of much benefit to consumers for value comparisons, especially if (as is usually the case) there are many standard sizes. And it is often opposed on the grounds that it reduces consumer choice.

Many countries, including Australia no longer have standard pack size legislation.

The ineffectiveness of the standard pack size provisions was a major reason why in 1998 the European Union (then the EEC) decided to make the provision of unit prices compulsory.

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@ijarratt I think it could be done and be very useful in a practical sense for a large range of but not all products, noting governments have a way of enabling business to do dodgy things.

As example, consider the nutrition labels. There is the amount per 100g, and the per serve, but the manufacturer can define a “serve” any way they want, and it often pushes the imagination. eg a 125g packet might be specified to have a 78g serve to make it look healthier, where in fact the entire 125g might be light on for most people. Regardless the packet is only 1.6 serves according to them and who buys 1.6 serves?

Using your per wash example, how much detergent is needed in a wash? 10g, 20g, 22.5g? How can one scientifically specify a test for a clean wash? Some detergents are better at grease, others pen, some wine, and some spaghetti sauce. Some detergents want you to use lots of it to buy ever more, some less so. You can see where this is going.

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Hello Ian. Good luck with your research and your campaign.
At first I did not see that your question was about on-line purchases.
I wonder just how many of the respondees might similarly have missed that part.
Personally I have no experience of online shopping to relate.
So I will merely give you my thoughts on unit pricing in general.
I have long admired Aldi’s unit pricing. For me, with metric, it is quite easy to make comparisons – as long as the price is per 100 grams or per kg. I merely multiply the per 100 gram price to get a price per kg.

Likewise for fluids, a per 100 mils price, just needs to be multiplied by 10 to give me a price per litre.

In both cases, this merely means moving the decimal point one numeral to the left.

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Hi Ian. Great job on getting the unit pricing system implemented in supermarkets. It would appear that some manufacturers will go to any lengths to disguise the unit price of their goods compared to that of their competitor, and I always consult unit pricing before most purchases. Unfortunately the supermarkets ploy of sometimes presenting this unit pricing information in small print, and sometimes hidden amongst other information on the price tag, does make the comparison task a bit more difficult sometimes.

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I totally agree! I always need to use my glasses because the unit prices are so small - same problem trying to read the labels on the items.


Unit pricing is a great idea (thank you) and I do use it, however it is often typed in such a small font that it is difficult to read without glasses (and sometimes with glasses)! A minimum size clear type font should be part of the process. We don’t always remember to take reading glasses to a supermarket.