Save Money Shopping: get the best value!

By April 30, 2017 No Comments

There is a lot of choice available in supermarkets these days. So much so that it can be quite confusing as to which brand item you buy and which size bottle/ packet/ can/ jar you select?

Brand is a personal choice; some people will stick to name brands as they believe them to be better, some stick to the no-name ‘home’ brands in order to save money.  But, the quantity (amount) you buy – whether you select the smaller size or the larger size of a product – can make a difference to your expenses over the course of the week, month or year, but I am not talking about buying in bulk…

Personally, I don’t have room in my house to buy in bulk and nor do I wish to. We are a household of only two people, so buying in bulk doesn’t often make sense for us, especially if the product is perishable (has an expiry date). However, my Grandfather taught me an invaluable tip when buying groceries, or any item for that matter, when different quantities are available. “Always choose the best value.”

Which is better value – buying 250ml or 500ml of a product?

The idea is to break down the cost per gram or millilitre etc and compare ‘apples with apples’. It may seem tricky at first, but it’s not and you can do a quick calculation in your head. After all, it is an approximation only. Some supermarkets already work it out for you on their price tags these days, for price transparency, you just need to look for ‘Price for 100ml’ or Price per 100g’ etc to be able to compare two products.

I’m surprised that more people don’t look out for this… they simply grab the same size product each time, depending on their habits. Here are 3 examples using different methods; just select a method which is relevant depending on how the product is sized/ priced.

 Example 1:

Product A 250ml $5.00
500ml $8.50

The 250ml bottle is priced at $5.00 and the 500ml bottle is priced at $8.50. Which do you select? Which is better value? To work it out you need to calculate the cost using the same comparable sizing. If you buy the 500ml bottle it will cost you $8.50.  As a comparison, if you were to buy 2 x 250ml bottles (also 500ml in total), it would cost you $10.00 (2 x $5.00); its more expensive than the larger bottle at $8.50.

So in this scenario, it would be better value to buy the larger 500ml bottle (you would save $1.50 for the same amount). 

This is an easy comparison as the bigger bottle is exactly twice the size of the smaller bottle.

 Example 2:

Product B 100g $2.60
150g $3.40

 The 100g can is priced at $2.60 and the 150g can is priced at $3.40. Which is better value?  If you buy the 150g can it will cost you $3.40.  As a comparison, if you were to buy 1 ½ cans of the 100g size (also 150g in total), in theory it would cost you 1 ½ x $2.60 ($2.60 + $1.30) total $3.90; which is more expensive than the larger can at $3.40.

So in this scenario, it would be better value to buy the larger 150g can (you would save 50c for the same amount. 

Whilst you can’t buy 1 ½ cans in reality, we are trying to compare the same gram for gram price. This would be the easiest way to compare the cans because the bigger size is exactly 50% more. Just calculate what 50% of $2.60 is and add it on to the 100g can price.

 Example 3:

Product C 500ml $3.00
800ml $6.00

The 500ml jar is priced at $3.00 and the 800ml jar is priced at $6.00. This may seem a little trickier because the larger jar is not perfectly twice the size of the smaller jar.  Instead it would be better to calculate the Price per 100ml.

In this scenario, it’s easier to simply find the cost per 100ml.

If you were to buy the 500ml jar it would cost you $3.00 which equates to 0.60c per 100ml

Step 1: 500ml / 100ml = 5

Step 2: $3.00 / 5 = 0.60c

The 800ml jar on the other hand would cost you $6.00 which equates to 0.75c per 100ml.

Step 1: 800ml / 100ml = 8

Step 2: $6.00 / 8 = 0.75c

So in this case, the 800ml jar is actually more expensive per 100ml and therefore doesn’t represent any savings to you, to warrant buying the larger jar. So in this scenario, it would be better value to buy the smaller 500ml jar.  


Do these comparisons often enough and it will become second nature to you and take only a couple of seconds to work out whilst you are standing in the supermarket. Or, use the calculator on your mobile phone to help you! Remember, some supermarkets already are doing this for you, you just need to look at the price tag!

If the product is a perishable item and you know that you will not use up the larger size before the expiry date…. then it generally makes sense to buy the smaller size, otherwise you will end up throwing away the unused amount, which is the same as throwing your money away. Therefore tis tip works the best for items that are non-perishable or for those perishable items that you know you will use up before expiry.



Disclaimer: This information is general in nature. It is based on the knowledge and experiences of the author and not intended to be taken as financial advice. It does not take into account the objectives, financial situation or needs of you or any other particular person. You need to consider your financial situation and needs before making any decisions based on the information. You may have to modify the information and do further research, for it to suit your personal financial situation. Therefore, before acting on the information, it is recommended that you consider its appropriateness to your circumstances or consult a financial adviser to assist you in doing this. 

Leave a Reply

Become a Money Messenger insider and get the latest financial secrets and strategies delivered to your inbox! Plus a special bonus: 10% off your first purchase!
We respect your privacy.