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



That would be ‘yes’. Why do you ask?


I love unit pricing but find not everyone is familiar with it and how it works (eg my aging parents). One comment is often if an item is on special, it contains the special total price, but not the equivilant unit price. So you cant compare unit prices if the item is on special or marked down


I find unit pricing very useful, except that one has to be careful one is not comparing apples and oranges (or mandarins, bananas…).

On a more serious note, the tea bag example is incredibly vexed. Manufacturer A sells 100 tea bags each weighing 1.2g for $5, manufacturer B sells 100 tea bags each weighing 1g for $4.50. That is, for 120g you can pay $5, or you can pay $4.50 for 100g - meaning that manufacturer A’s bags cost 4.2cents/gram while B’s cost 4.5cents/gram.

(Please note that in the hypothetical example below, I am unsure whether ‘net’ tea bag weight is considered to be inclusive or exclusive of the label, string, filtering material etc. - I have assumed that it is inclusive, though this does not ultimately matter.)

You approach manufacturer B to point out that they are deceiving their customers, and they say “Well actually, you are only looking at the surface. Our tea bags are made with the latest, high quality and low weight papers. We use a cotton polymer staple for the dangler, and this cuts weight significantly compared to those environmentally damaging steel staples our competitors use. The amount of tea we put into our bags slightly exceeds those of our competitors. Moreover, if you look at our ‘half-bag’ products, which contain only half the tea of our normal bags but use an extra-strong variety of the plant that we developed in-house, have just been awarded the Golden Tea Taste Award for the third year running! How can you suggest that our tea is in any way ‘watered down’?”

This is the same problem the consumer encounters when faced with a new ‘Ultra-tough’ detergent or laundry powder - if the manufacturer is correct in their claim that this product costing 1/3 more is twice as powerful, then it is still a saving over the standard ‘super-tough’ product. And that is a big IF.

It is often difficult to identify whether the shop has included a unit price for items that are ‘2 for $x’ - I have often seen labels where I cannot see a unit price for the discounted multiple.

Now for a minor subject change, to…

The supermarket code of conduct

No, I am not referring to the more recent Food and Grocery Code of Conduct, but to the agreement supermarkets entered into decades ago when they started introducing scanning at checkouts. Consumers kicked up a stink (and rightly so), saying “if the product doesn’t have the price on the label, how do we know you’re charging the right price?” The supermarkets hummed and hawed, and eventually agreed to this code of conduct. One of the obligations that is placed upon participants (and I think participation is voluntary, but don’t think any of the majors has dared drop it yet) is:

  • If a product scans for a higher price than the shelf price, the consumer is to be given that item for free. If they have purchased more than one, the first is free while all others are to be charged at the lower price.

Forgotten it? Your supermarket loves you - and in fact tries very hard not to remind you of its obligation. At least once a week I catch Coles out for mismatching the shelf and scan price. There are one or two loopholes, but almost always I walk away with a freebie. Do not assume that the staff member will ‘remember’ the code of conduct - watch what they do, and correct it if necessary. I think most of the locals know me by now - sometimes they don’t even check the shelf!

This sometimes also applies when the label on the shelf is for another product. If the supermarket has been silly enough to stack the fancy-pants ice creams above the label that shows the price for their home label product, that is their mistake and to their cost. (If only one or two items are above the wrong price, then bad luck.)

The items most likely to be affected are ones that have recently gone on sale or had a price change - so keep your eye out, even when buying your groceries online. This is an easy way to save a lot of money.


Thanks for your comments.

  1. per each or per 100g for the unit price of items like tea bags is a tricky question. I am increasing thinking that where ever possible the retailer should provide both.
  2. variation between products, such as laundry detergent, in how much is needed to do the same job is also a tricky question. At the moment i favour providing the unit price per unit of output (eg per wash) but only if there is a standard for the amount needed per unit of output. And, again maybe the unit price per unit of actual product should also be provided.
  3. The unit price does not have to be provided for a multibuy offer like 2 for $X if it applies to more than one size of pack . An example is bars of chocolate either 200g or 220g. So check if this is the situation when the unit price is missing. If the offer is for only one size of product the unit price has to be provided and if it is not let the ACCC know - ph 1300 302 502

This is a topic that I have been meaning to seek views about here because, as you rightly observe, the arrangements have changed greatly in recent years, including no longer having in store signs about their code/policy . It would be interesting to see if other consumers are experiencing lots of errors and to know how well the retailers are complying with their policies when consumers complain. It would be great if put this up as a topic here.


How does one define a unit of laundry? Would this be as meaningful as auto fuel consumption? How about washing up detergent per wash up? What is the AS for a sink of dirty dishes, if that makes a point.

My real question is at what point does something lose touch with practical reality for the sake of including a metric? The majority of consumers use some things by weight but other things by item, and for most products one or the other makes sense for the purposes of a practical price comparison. Consumers will use unit pricing to purchase, but after buying something, especially products in the twilight zone of what is or might be important, each of us will determine if we need more or less ‘per dose’ and if we felt it good or poor value and that will feed back to the next shop.

It might not be mandatory but I routinely see unit pricing shown as a range where all units are the smaller and all are the bigger, eg ‘$1.00 to $1.20 per 100g’.

The more interesting problem I see is some products are sold by unit and others by weight. Asparagus is often sold by the bunch, whatever a standard bunch is, yet google returned a ‘bunch’ as an average 150g, or 200g, but mostly just as a ‘bunch’, vendor dependent, and others selling it by kg. Some grocers have flip flopped selling it by bunches on sale and kg when not on sale, noting the prices were similar indicating cynical pricing games may be at play.

Whatever unit pricing is, it should be mandated that some products should be sold only by item and some only by weight. That would be a good start in a step that should be achievable without excessive academic discussion on which is best for each product. As soon as ‘uses’ are introduced it becomes subjective, more debatable, and thus more difficult to enact.

Just my $0.02 :wink:


Many thanks. Detailed comments like these are really helpful for the development of consumer positions/policies.

Re unit pricing per unit of output: I agree that output/performance differences between products can be considered to be a quality difference the shopper needs top take into account when comparing unit prices per unit of weight/volume. But if the differences are very great or if, as with laundry products, the unit pricing unit of measure might be weight/volume/tablet/capsule a case can be made for the unit price to output related However, to protect consumers and for comparability I think that unit of measure should be standardized, seems to be the case for laundry products in the EU. of course, even with standardized per wash unit of measure people will still vary in how the product performs for them and have take account of that. But at least the base unit will be standardized and more reliable than the alternatives.

Re providing a range of unit prices for multi buys of different size. Interesting that you see it provided routinely. I need to check a few supermarkets again. Last time I did so I thought only Aldi did it. I think it is helpful and if nothing else reminds people that pack sizes vary.

Re requiring the use of only one unit of measure for selling a product.
I support this and the max use of weight and (where relevant) volume n ot count/each. But the difficulty will be in deciding the unit for each product. At the moment there is along list of products that can be offered for sale by count or by weight. And, retailers seem to be increasingly using count as the unit of measure. I am trying to get this addressed in the proposed review of the trade measurement legislation.


Further to my suggestion that you put this up as a topic here, I am now aware that it was the subject of this July 2016 post Barcode Scan Price Errors


Interesting thread - thanks, @ijarratt. You may have intended to include the link, but I tracked it down. For other curious minds it can be found at:

Barcode Scan Price Errors

So far it has posts commencing in July 2016, while the most recent was made in July 2017 - making for quite a lengthy read even without my participation :wink:. (I am not saying that my posts here are verbose, but I am not saying that they are not verbose.)

In summary [cough] , it appears that Woolworths, Coles and Aldi all have policies based upon the Supermarket Code of Conduct, stating that:

  1. If an item scans for a price higher than was marked on the shelf, it is free.
  2. If a customer is buying more than one item affected by point one, the first item is free and subsequent items are to be charged at the lower price.

It appears that certain item types may not be eligible for this policy, and there may be other limitations. In a post on 04 April, @Raym stated that Coles applied a maximum item value of $50, and exempted the following items from this policy (I cannot vouch for this list, but quote it as useful information from the other thread):

  • Items without a barcode or PLU
  • Third Party Gift Cards
  • Tobacco or Liquor products

Interestingly, I have found (as have several posters in that thread) that staff knowledge of these policies - in a wide range of ‘fine shopping establishments’ - is incredibly varied. I have plenty of experience in correcting staff at the local supermarket when they start typing in the ‘discounted’ price, and while some staff quickly correct their mistake others look at me blankly before figuring that it’s just easier to do what I’m saying, or wander off to find a supervisor who has a clue.

The local Coles has never turned down my insistence on applying their policies - but I don’t know whether this is because they know what they’re doing, or simply because they can imagine the kind of loud, business-unfriendly tantrum that would result from a ‘wrong answer’.


I am still enjoying Unit Pricing - thank you to ijarratt for advocating it. I use it mainly to compare like with like - eg to see if the 287g pack on special is better value than 1.14kg Weet-bix. Bigger used to mean better value, but I find that rather variable now. Even to the point of possibly deliberate deception.

Another gripe is the Sales tag under the wrong item, or it referring to only one flavour. I now check the barcode, the last few numbers on tag & packet. Another gripe is fresh fruit & veg with no price, which I now assume is “too expensive”, if I asked I would be putting it back. Another is marked down eg day old bread where the big fluro label is missed and the barcode is scanned for full price.

Only one venue I use is big enough for unit pricing. Unfortunately I am far too busy at the checkout uploading, moving and packing to watch prices (it’s not Aldi). When I get home it’s too late, and next trip is not for a fortnight - an hour’s drive. So they make a bit out of me each time.


Thanks for any work you did for unit pricing. I use it online and in-store and only buy when my items hit the low price per unit. Shop specials are often not the item with the lowest unit price so I think people need to be more educated about that.


Unit pricing could be improved. See our suggestions to make the system work better here:


Signed the petition as well as read the article. Hopefully @ijarratt will also have somethings to add to strengthen the campaign if they aren’t already involved.


This unit pricing example surfaced on Twitter from @ showing loose chillis at $24/kg and the same plastic packaged chillis for $150/kg.


They have to cover the costs of the expensive plastic packaging and all that labour to pack them.



That’s a spicy markup! :hot_pepper:


Brendan. Thanks for this. It is one (albeit a very extreme one) of many examples of major differences in the unit price of identical or very similar products.

However, the example is also interesting for 2 other reasons.

  1. If you buy the packaged chillies you probably get more than you need and may end up wasting some very expensive chillies, unless you put them in the freezer. Buying loose, and at the much lower price, you can buy the exact amount you want and have no wastage.

  2. The store has unit priced the loose chillies per kg, because the trade measurement laws requires that if loose products are sold by weight they must be priced per kg. However, the packaged chillies, which are covered by the unit pricing code administered by the ACCC, have been unit priced priced per 100g. This is wrong because the code, which only applies to fixed measure packaged products, requires that fruit and vegetables sold by weight be unit priced per kg. And, if the chillies are regarded as herbs or spices the code (probably trying to cater for dried herbs and spices not fresh) requires that they be unit priced per 10g. This is why achieving greater consistency in the unit of measure used to unit price identical or similar products needs to be an objective of the current reviews of the unit pricing code and the trade measurement laws…


Would it be a surprise that not all shoppers care to look at unit pricing?

Shop keepers are astute when it comes to customer behaviour. If the greater majority of shoppers rely on unit pricing in most purchase decisions would this encourage store keepers to provide better and clearer unit pricing, or none at all? One option is not legal mostly anymore.

With a choice between a supermarket that does unit pricing very well and one that does it poorly where would astute shoppers tend to shop, all other things being equal?

So far no one is lauding the performance of any supermarket chain in delivering consistent and easily read/understood unit pricing.

Perhaps Choice shoppers are inherently more likely to refer to unit pricing. Hence any survey of Choice members on the topic or group opinion is likely to be biased. I raise this as the extended family which spans 3 adult generations rarely considers unit prices. Tomatoes and mince excepted!

Are there any reliable surveys of the greater shopping community, their attitudes towards unit pricing, and how often unit pricing is a deciding factor?

Perhaps this outlook might show a socio economic factor, just as some past surveys have suggested there are suburbs which are more expensive for groceries than others. IE shoppers with high disposable incomes are more likely to decide based on individual perceptions of high quality, performance and convenience. Is that where the margins are greatest?

That suggests the profitability of a supermarket relies to a large degree on being able to exploit consumer ignorance or indifference. I hope the Choice Community realises what the outcome will be for all the Colesworth shareholders as Choice as an organisation continues to improve consumer outcomes. :wink:

To be fair dinkum the big number on the shelf price should be the unit price. It is still how some of us buy tomatoes or choose not to when you see $12 /kg. The unit price is the true measure of value. The purchase price is the cost of selecting the quantity required. Oh, how clever are shop keepers?


Just supermarkets? :wink:


The national survey conducted for Choice in 2018 is the most recent comprehensive survey i know of.

In its submission to the govt’s review of the unit pricing law Choice’s submission said this about the survey:

In October 2018, CHOICE conducted a national survey to understand consumers’ use and understanding of unit pricing. We found that unit pricing is a highly used and well-liked tool with 76% of people using unit prices all or most of the time. Almost all (96%) of these people find it helpful, with making it easy to compare prices the most common perceived benefit.

69% of people said it makes it easy to compare prices regardless of pack sizes.

● 59% of people said it saves them time working out which product provides the bestvalue.

● 54% of people said it saves effort working out which product provides the best value.

The survey also showed that 64% of those who used unit pricing all or most of the time had experienced problems doing so.


This is because there are major problems with how unit prices are provided at all supermarkets.

The main in-store problems are inadequate display, use of wrong or inconsistent units of measure and non or intermittent provision.

These problems also exist at some online selling sites plus imprecise product search functions and non provision, or lack of consumer awareness, of a sort by lowest unit price function.

IMO Aldi used to do a quite good job with its shelf labels (except for special offers and price reductions) but has gone backwards since it decided to greatly reduce the print size not use bold font for the unit price on many shelf labels.