/ Food & Drink

Why’s it so hard to work out the cost of a banana?

Illustration asking how much for a banana?

Seven mini bananas will cost you 99p for the bunch (or 14.1p each). Loose bananas cost 68p per kg. From this information, can you work out what’s cheapest to buy? Welcome to world of confusing supermarket unit pricing.

With a busy job and excitable children, a visit to the supermarket needs to be a simple and speedy affair.

I don’t have the time to pore over supermarket shelves to work out the best price for my purchases.

Unit pricing is a great idea in theory. It’s a useful tool for people to compare food prices and choose the best value product.

But our research shows unclear and inconsistent use of unit prices in supermarkets is preventing cash-strapped consumers from being able to work out which products are cheapest.

Supermarket sweep

We sent our supermarket shoppers on a mission to visit all the major supermarkets at a number of locations across the UK to see the extent of the problem.

Their research highlighted some interesting issues – for a start, unit pricing was sometimes being used by referencing the quantity and sometimes the weight. What’s more, they were often not being shown for multi-buys or promotions and some pricing was too small to read – or non-existent.

Along with the banana example we found red peppers in 500g packs on sale for £2.09 or £4.18 per kg next to packs of three mixed peppers priced at £1.65 or 56p each. Confused? Don’t worry, so am I. These are just a couple of examples we found – see more in our gallery (for further information about each image, visit our Flickr page):


Clear, consistent food pricing

Which? wants clear, consistent food pricing where the unit price is prominent and easy to read. We also want consistency in the units used on all products and for multi-buys and promotions to show the unit price.

Is unit pricing a bugbear of yours? We’re going to up the pressure on government and retailers in the coming months to simplify unit pricing for you.

If you feel strongly about the issue we’d love your views or examples of confusing unit pricing. If you’ve caught the issues on camera, tweet us your photo or email it to which.campaigns@which.co.uk. We’ll add the best of the bunch to our online gallery.


Seven mini bananas will cost you 99p for the bunch (or 14.1p each).
Loose bananas cost 68p per kg

Can be worked out without too much difficulty which is the cheaper
deal or offering better value for money in terms of edible stuff.

Waitrose provides electronic weighing scales at its Fruit & Veg section
that I do not hesitate to use with respect to checking anything and
everything (if need be) I buy at the supermarket. In any event I carry a pocket
calculator to ensure checkout receipt tallies with my own total. Yes…
Waitrose does make mistakes too in charging, in actually overcharging that
I’ve brought to their attention on numerous occasions.

What I find somewhat disconcerting or unsatisfactory is when individual items priced at
say £2.00 each can be had for £3.00 if you buy two of them and when these
items are reduced in price because of proximity to sell-by date, each item is reduced to
a price that sits somewhere between £1.50- £2.00, typically £1.75. This practice I noticed
is also perpetrated at both Tesco and Sainsbury. In other words, you are having to pay
MORE for just ONE item of their staler food and that can’t be right, can it? Not everyone
would want to buy the surplus portion for storage in the fridge or freezer for subsequent
consumption as to their 2 items for £3.00 offer in the simple example given.

We have just returned to UK after 12 years living on the continent. I simply do not remember this problem there. Everything seemed to be priced per kg or per litre making the sums very simple. I have recently noticed that all the UK supermarkets seem to have bargain offers that are not really bargains. Every offer has to be carefully checked to ensure that you are not being ripped off, be it jars of coffee or tins of tuna never mind the fruit and vedge nightmare.

Who pays the penalty, in the main, the less well educated, the mentally challenged, and those in a hurry. The less well educated and the mentally challenged are often the poorest in our communities as they are unable to get a job. Once again it seems to be the poor paying more than the rich. The super markets should be ashamed of themselves; fleecing the needy is not something to be proud of.

I have read in one if not more of the posts that trading standards need to get involved, but if the supermarket is not breaking the law what can they do. You cannot shop elsewhere, as all the supermarkets seem to be as bad as each other. The only answer is probably a new law which states that all items are to have a price per kg or per litre. Now I hate having the government get involved in legislating on such issues, but there does not seem to be an option. Perhaps they would be better drafting such legislation rather than contemplating new legislation banning smoking in cars.

Perhaps I am shooting myself in the foot, as there will be less of the real bargains to be had. I am lucky, I can still do mental arithmetic, but for how much longer, ages catches up on us all.

In the bad old days when I was a young lad, it was the wide boys that ripped people off. Now everybody is at it. The greedy green eyed monster is everywhere, supermarket chains, banks etc, etc. Everyone wants to make a fast buck and nobody seems to care who suffers. I will now get down from my soap box.

Pete says:
8 December 2011

“What I find somewhat disconcerting or unsatisfactory is when individual items priced at
say £2.00 each can be had for £3.00 if you buy two of them and when these
items are reduced in price because of proximity to sell-by date, each item is reduced to
a price that sits somewhere between £1.50- £2.00, typically £1.75″

Well I bought two 10” pizzas from Asda, normally £2.50 each or 2 for £4.00.
However one I picked up was discounted to £2 (50p off) because it had to be eaten that day.

Guess how much I was charged – £3.50 or £4.00?

Nope, £4.50. When I queried this at Customer Services I was told that discounted items did not count towards multibuys. So my normal price pizza plus my discounted pizza cost me more than two normal price pizzas would have done.

From the nature and content of your comment, I really don’t think you have got it. I really do not think you have shopped in a supermarket on a weekly basis. Supermarkets seem to be a novelty and a mystery to you.

Please tell me, a shopper who surprisingly, does not find Waitrose as ‘good value for money’ or in plain English finds Waitrose to be ‘expensive’. Prey, tell me, how it is OK or straightforward for me as a shopper with calculator in hand, and scales to hand, not available in Aldi nor Lidl, but certainly not having access to Waitrose magical ‘electronic scales’ to compare;
“Seven mini bananas will cost you 99p for the bunch (or 14.1p each).
Loose bananas cost 68p per kg”
Are you suggesting that Waitrose scales can count and weigh the items and then do a comparison? You don’t get it do you? Or am I one of the “the mentally challenged, and those in a hurry”, how nice. Possibly, I fall in to both categories as I can’t compare the incomparable unlike your good self, a very especially talented Waitrose shopper.

What I do not understand, and I have read the Which campaign notes, when did the world change? When or what change in legislation allowed supermarkets or any other retailer to prevent shoppers from comparing prices of goods by weight? When did that happen and why did it happen? The Which campaign fails to mention how or when or why?

I know that supermarkets are very happy if consumers cannot work out the cost of what they are buying. It is ‘confusion marketing’. It is deliberate; it is underhand and it we are all being deliberately conned. The politicians and the retailers are content that consumers are tricked rather than informed. And if I was totally cynical, or a realist, Which seems to be happy that it produces a campaign that that they can promote, but not too loudly as they might upset the retailers.

I’m an Chartered Accountant so i feel comfortable with numbers and i’ve noticed this ‘Marketing scam’ by Tesco’s, Sainbury’s and Asda of late. I normally can’t be bothered to calculate what is the best deal. So well done ‘Which’ for highlighting this! I’ve seen it happen on all food stuffs from vegetables to snacks to meat and poultry etc

I’ve repeatedly told Tesco’s about various examples of confusing unit pricing, and all they say is pricing is set by head office. One employee also agreed that Head Office were useless.

Another said there’s no industry standard for this, My reply, So what be consistent amongst you’re own pricing.

I don’t have time to pore over the shelves looking for labels and doing the mental arithmetic either so it’s about time this issue was taken up strongly. The only thing that will get these supermarkets to change their ways is publicity so please keep at it.

Well what I say is that when push comes to shove and you have a pack of 3 for £3 and single items priced at £1.25 or above, you should just open the pack of 3 and demand to pay ONLY £1 since that is the price set for the pack.

In so doing you leave the wasted packaging behind as well, reducing the infill waste.

Sorry – The law states there is an offer and an acceptance – so you would be breaking that law. – I hope the shop prosecutes you for damaging their goods. as an example.

I agree in one sense, that if I only want one little gem lettuce then why should I pay for two knowing that I will throw the second away.

If there is an offer and an acceptance the offer is made on the shelf but the acceptance is when the item is paid for. If the store refused to allow me to have the discounted item for £1 i would shrug my shoulders and leave it.

They could try to prosecute me but it would cost them more than the items were worth and they would have to jail me as I wouldn’t pay any fine and I would demand trial by jury of my peers as well!

To me it’s simple – take the mini bananas and weigh them on the scales usually provided – then you will have the price per kg for both items – the choice is easy.

At least it was when I taught Everyday Maths at school – has the standard of “sums”dropped that low?. I don’t think so – Though the level of laziness has grown.

I’ve never been that busy that I couldn’t spend a minute literally to check..

Robin Paice says:
18 November 2011

It is pleasing to see that at last Which is trying to tackle this issue. However, it is all very well to name and shame the supermarkets, but what is really required is a change in the law – and in its enforcement. The loopholes for “countable produce”, open containers, mixed products and exemptions for “small shops” should be closed. Above all the law should actually be ENFORCED by Trading Standards Officers – especially against shopkeepers and market traders who do not even display prices in legal (metric) units, with the result that it is impossible to compare value for money.

Yes, enshrining unit pricing in law is long overdue. It should include agreed units for any commodity and ideally the unit price label should be the most prominent price indication.

DaveSuffolk says:
18 November 2011

Of course any unit price can be worked out if you have a pair of scales handy and a calculator (or you’re good at mental arithmetic). But the point of having a comparable unit price is to save you that hassle and educate those who can’t or won’t do it. So if the unit prices can’t be compared they are useless and we might as well go back to ‘let the buyer beware’ as we did 100 years ago.

Apart from the same items being sold sometimes per item and sometimes per Kg, I’ve also seen some labels comparing price per kg and price per litre for the same type of product and sometimes it is offered as price per 100 grams against price per kg. I know all these can be converted by a competent mathematician but most people won’t bother.

Another difficulty is when there is a special offer such as buy 2 save £1. The unit comparison is normally only on the price for one and doesn’t take account of the saving.

michduncg says:
20 December 2011

‘it is offered as price per 100 grams against price per kg. I know all these can be converted by a competent mathematician but most people won’t bother.’

The beauty of metric is that you only need move the decimal point to convert prices per 100g into price /kg. Surely even someone not to conversant in maths can grasp this simple concept – a lot easier than it would be if we were still using lbs and oz’s in the supermarket.

TonyW says:
18 November 2011

My local Nisa supermarket has unit pricing on its milk labels; sadly the 90p litre is labelled “90p/litre” while the 45p 568ml/1 pint is labelled “45p per pint”. Not very helpful to customers trying to work out which is cheaper! The sooner odd old imperial sizes disappear the better for consumers.

People who claim not to have time to check out the most economic prices, to be honest, do everyone else a disservice and will perpetuate the very problem they are complaining about. Get yourselves more organized; don’t just whinge and expect everyone else to do things for you. All major supermarket outlets provide scales for weighing items of fruit and vegetables. Yes, smaller outlets lack these but what’s wrong with a bit of simple mental arithmetic? Oh yes, I forgot; fewer people seem able to do that these days. They probably don’t have the time…….
Sorry, but it is fatuous to expect supermarket chains to be altruistic. They are not charities; they are in the business of making the most profit they can. But there is no need for us to make their lives easy.

The lack of consistency is annoying but presumably the information is correct.

Not always. I took a photo of a shelf label for Seabrook crinkle cut sea salted crisps showing a price of £1.28 for a 6 pack, equivalent to £21.34 per 100g. There is something seriously wrong there. Tesco of course.

Another problem is that unit pricing is unhelpful with supermarket offers such as buy two and get one free. The unit pricing refers to the cost of a single pack, making it difficult to compare the offer price with that of other brands.

Maybe we need a phone app to make these comparisons easy. That seems a more practical solution than expecting supermarkets to get their act together.

Alison Lowrie says:
18 November 2011

Tesco seem determined to try and confuse shoppers over its multi-pack soft drinks. A pack of 12 Tesco coke used to cost £1.99, then that increased to £2.69. Then suddenly 12-packs became eight packs and six packs became four packs. I challenged our local branch manager when the eight pack, which was priced at £1.99, in the space of a week went up 70p to £2.69, the original price of the 12-pack. The following week the price was back down to £1.99. You get the feeling that they were just wondering whether anyone would notice…daylight robbery I called it.

Rebecca Parris says:
18 November 2011

I once mischievously asked a supermarket assistant if they had data on the density of mayonnaise as some of it was priced in £/kg and some in £/litre.

I don’t think they employ too many scientists in supermarkets. If they did, I’m sure that they would sort out the lack of consistency in pricing as a priority.

Getting off topic, but I once went into a DIY supermarket and said that I wanted a piece of planed timber and gave the dimensions in cm. The young man explained that he could not help because all their timber was in millimetres.

I agree the unit pricing rules need to be enforced; just a walk around any supermarket will reveal incorrectly or confusingly labelled products. But I think the rules also need extending so that offers (BOGOF etc) have to be priced both as a single item and as the offer. Without that, you just can’t compare unless you are mathematical genuis and have a lot of time on your hands.

Tatto Couligian says:
18 November 2011

I noticed that one employee of Tesco’s thought “head office was useless” for not clarifying the confusion about unit (etc) pricing. They are not useless, they are simply clever. They WANT to confuse us so that we do not find ways of spending less.

That is why a campaign by Which? is very necessary, in order to force the Government into action in favour of the consumer for a change

I’ve often wondered if the people who type up the prices aren’t just bored and do it for a laugh.

But seriously, for a chain like Tesco’s to have misleading of incorrectly priced special offers you must wonder whether it is on purpose. A store manager will say we have over 20k items you should expect a few mistakes, yet say they have 3000 stores that must mean arond 3000 people putting the prices on the shelves and more restocking the shelves, a few printing the labels, yet not one has spotted the mistake and done anything to rectify it. And no doubt they have a quality dept too. Smacks of corporate policy to mislead to me.

“Sorry – The law states there is an offer and an acceptance – so you would be breaking that law.
– I hope…………..” (richard)

The law MAY take the view that it’s only an invitation to treat, you offering to buy
what’s offered for sale when you put it in your shopping trolley/basket…. acceptance is
created when you pay for the item(s) at price specified at the checkout that constitutes
the crucial element of consideration in the Contract of Sale thus effected, (as
indeed is consideration required in any other legally-binding contract though
not necessarily always in money or money’s worth)

Richard must be a supermarket boss. It is not quite as simple as he states in having to use scales to weigh a large portion of the veg on offer to gain a consistent weight-for-weight comparison. this is time-consuming and should be unnecessary. It is clear that the supermarkets are deliberately attempting to mislead customers. What other reasons for inconsistency? Like so many other customers I am frustrated and annoyed by the attitude of supermarkets on this. Good for Which. Please keep up the pressure, or install a “Richard” to do all the weighing for us.

Helenat7 says:
18 November 2011

A mini bunch of bananas in a pack, compared with loose bananas? There can’t be a comparable unit price because, fundamentally, they’re different products. Different size, shape, ripeness, variety, even ‘desirability’.