Supermarket Showdown: An Honest Price Comparison of Coles, Woolworths, IGA & Aldi

The weekly grocery shop. For many Aussie families, it’s a tactical mission that can make or break the household budget. You walk in with a list and the best of intentions, but as you navigate the aisles, a thousand questions pop into your head.

Is this brand of coffee really a good deal? Should I get the home brand mince or is the branded one on special cheaper? I wonder if this would be cheaper at the supermarket down the road?

For years, the great debate has raged in households across the country: Who is really the cheapest supermarket in Australia? Is it the everyday low prices of Aldi, the convenience of Coles, the fresh food focus of Woolworths, or the local specials at IGA?

Common wisdom often points to one winner, but is that the whole story? We decided to put the rumours and assumptions to the test. Armed with a typical Aussie shopping list and our secret weapon—the Save On Groceries (SOG) app—we launched our very own Supermarket Showdown.

The results might just change the way you shop forever.

Methodology: How We Ran a Fair Test

To get an honest answer, we needed a clear and transparent process. Here’s exactly how we did it:

1. The "Standard Aussie Grocery Basket" We created a shopping list of 17 common items that find their way into most trolleys. The list includes a mix of fresh produce, pantry staples, dairy, and protein to give a realistic overview of a typical weekly shop. We focused on the most popular home brand or equivalent options to ensure a fair comparison.

Our Basket Items:

• White Bread (700g loaf)
• Full Cream Milk (2L)
• Block Cheese (500g, tasty/cheddar)
• Free Range Eggs (12 pack, 700g)
• Beef Mince (500g, regular)
• Chicken Breast Fillets (per kg)
• Broccoli (per kg)
• Brown Onions (per kg)
• Carrots (1kg bag)
• White Potatoes (2kg bag)
• Pasta (500g, spaghetti/penne)
• Pasta Sauce (500g jar)
• White Rice (1kg bag)
• Instant Coffee (100g jar)
• Olive Oil (500ml bottle)
• Toilet Paper (8 pack)
• Multipurpose Cleaner (500ml spray)

2. The Tool: The Save On Groceries (SOG) App We used the SOG app to find the prices for every item on our list at Coles, Woolworths, Aldi, and IGA. The prices were recorded on a single day (the first day of the weekly special cycle) to ensure we were comparing apples with apples (literally!). The SOG app pulls data from the latest catalogues and online prices, giving us a real-time snapshot of the market.

3. The Contenders We compared the four major players in the Australian supermarket game:

• Coles
• Woolworths
• Aldi
• IGA

For Aldi, we used their standard everyday pricing, as their model is less about weekly specials and more about consistent low prices. For IGA, we used their advertised catalogue specials, acknowledging that prices can vary between their independently owned stores.

The Results: The Grand Total

So, after "visiting" all four supermarkets via the SOG app and filling our virtual basket, what was the final damage to the wallet?

Here is the total cost of our 17-item grocery basket at each supermarket:

As the chart clearly shows, there was a definite winner on this particular shopping day. Aldi was the cheapest by a significant margin, coming in almost $10 cheaper than its closest competitor, Woolworths. The total difference between the cheapest (Aldi) and the most expensive (IGA) was a staggering $19.25.

That’s nearly $20 of savings on a single shop—money that could go towards another meal, petrol, or the family savings account.

The Price Breakdown: Item by Item

The total cost is one thing, but where do the big savings and losses actually come from? The devil is in the detail. Let's break down the basket item by item.

(Note: Prices are illustrative, based on a single day's comparison, and will vary.).

Analysis: Digging Deeper Than the Grand Total

The results are stark. In our snapshot, Aldi was the undisputed champion, winning every single item. This aligns with broader industry analysis, such as the quarterly CHOICE Supermarket Price Survey, which consistently finds Aldi to be the cheapest option.

But does this mean you should abandon all other supermarkets and shop exclusively at Aldi? Not so fast. The real story is more nuanced.

The Flaw in the "Snapshot" - Why Prices Change Everything

This price comparison is a photograph taken on one specific day. Next week, it could look completely different.

This is the most critical takeaway for any savvy shopper. Coles and Woolworths run on a model of deep weekly specials. While their regular "shelf price" might be higher, their discounts can be dramatic.

• Scenario 1: Next week, Woolworths might have a half-price special on that exact 100g jar of instant coffee, bringing it down to $2.75. Suddenly, it's significantly cheaper than Aldi's price.
• Scenario 2: Coles could put their 8-pack of toilet paper on a "2 for $6" deal, making the unit price per roll cheaper than Aldi's.
• Scenario 3: IGA might have a "Manager's Special" on beef mince for $6.00, beating everyone.

Relying on one store's reputation means you will inevitably miss out on these powerful, budget-altering specials at other stores. Store loyalty doesn't pay; deal intelligence does.

The "Cherry-Picking" Strategy

The ultimate way to save is not to pledge allegiance to one supermarket, but to "cherry-pick" the best deals from each.

• Get your pantry staples and most fresh produce from Aldi.
• Check the SOG app for half-price specials on branded goods at Coles and Woolies.
• Pop into IGA for that one specific meat or deli item that's on a killer deal.

This sounds like a lot of work, but it’s precisely the problem the SOG app was designed to solve.

Your Secret Weapon for Consistent Savings: The SOG App

You can't be expected to visit four different websites and sift through catalogues every week. Your time is valuable. The SOG app does the heavy lifting for you, turning a time-consuming chore into a simple, 2-minute task.

• Build Your List: Before you shop, add all your items to the list builder in the SOG app.
• Instantly Compare: The app will show you the price of each item at Coles, Woolies, Aldi, and IGA, highlighting the cheapest option for everything on your list.
• See the Specials: The "Specials" tab is your goldmine. See all the half-price and discounted items at a glance and plan your meals around them for maximum savings.
• Make an Informed Choice: You might find that 80% of your list is cheapest at Aldi, but two big-ticket items are on a massive special at Woolworths. This allows you to make a quick decision: do one big shop at Aldi, or a quick second stop at Woolies to save an extra $10? The power is back in your hands.

This data-driven approach also helps with other smart strategies, like knowing when to stock up. For more on that, check out our guide on Why Buying in Bulk Doesn’t Always Save You Money — and When It Does.

Frequently Asked Questions (FAQ)

Q1: Does this result mean I should only shop at Aldi? 

Not necessarily. While our test showed Aldi was cheapest for this specific basket, the key takeaway is that specials at other stores can often beat Aldi's prices on individual items. The smartest strategy is to use the SOG app to get the best of all worlds.

Q2: Why was IGA so much more expensive in this test? 

IGAs are independently owned, so their pricing structure is different. They can't always compete with the buying power of the big three. However, their weekly catalogue specials can be extremely competitive, especially on meat, deli items, and local produce. The SOG app helps you spot these specific IGA bargains without having to do your entire shop there.

Q3: How often are the prices updated in the Save On Groceries app? 

The app is updated regularly to reflect the latest weekly specials and catalogue prices from Coles, Woolworths, Aldi, and IGA. This ensures you have the most current information right when you need it—before you shop.

Q4: What if I prefer a specific brand, not the home brand?

No problem! The SOG app allows you to search for any item, including your favourite brands. You can type "Moccona Coffee" or "OMO Laundry Powder" into the search bar and see who has it on special this week, ensuring you never pay full price for your preferred products again.

The Final Verdict

So, who is the cheapest supermarket in Australia? Based on our snapshot and wider reports, Aldi consistently offers the lowest overall price for a standard basket.

However, the smartest shopper knows that the title of "cheapest" is fluid. It changes every single week with every new catalogue. The real winner of the Supermarket Showdown isn't a store; it's the shopper who is armed with the right information at the right time.

Stop guessing and start knowing. Take control of your grocery budget and make sure you're getting the best possible price on everything you buy, every single week.

Download the free Save On Groceries app from the Google Play Store & Apple IOS Store today and declare victory in your own Supermarket Showdown!