Bottled water price comparison Australia: which bottle is really cheaper?

Bottled water price comparison: read per 100mL, not the bottle

The quick answer: ignore the size of the bottle and read the unit price. Then pick a size you will actually carry and drink, and check the price history before you stock up.

Water is the easiest thing in the shop to overpay for. It all looks the same, the bottles come in a dozen sizes, and the shelf tag only tells you what one bottle or one pack costs. The number to compare is what you pay for each 100mL.

We make Discount Trolley, so the bias is obvious. The app shows the unit price in search and on each product page, right under the shelf price. On water that line reads per 100mL, so a 600mL bottle, a 4L bottle and a 24 pack can be lined up on the same number.

• Unit price beats price per bottle.
• Small bottles cost the most per litre.
• Check the price history before you stock up.

Small bottles cost the most per litre

When we checked Coles in Discount Trolley on 17 October 2026, the Coles 1.5L spring water worked out to 7 cents per 100mL. A name brand 600mL bottle on the same screen was 43 cents per 100mL, about six times as much for the same amount of water. The name brand 1.5L bottle sat in between at 23 cents per 100mL.

The house brand 600mL bottle tells the same story. On that day it had the same shelf price as the house brand 1.5L bottle, so it worked out to 17 cents per 100mL against 7 cents. Same shelf price, much less water.

Small bottles are handy for the car, the gym bag or the school bag. If you buy them every day, it is worth filling a reusable bottle from a big one instead.

• A small bottle is a convenience buy.
• Same shelf price does not mean same value.
• Refill from a big bottle when you can.

Bigger is not always cheaper: 4L bottles, casks and multipacks

You would expect the biggest bottle to win every time. It does not. At Coles on 17 October 2026, the Coles 4L bottle worked out to 9 cents per 100mL, more than the 1.5L bottle at 7 cents. The Coles 10L cask came out level with the 1.5L bottle at 7 cents, and the Coles 8 pack of 1.5L bottles was the lowest of the Coles house brand range we checked at 6 cents.

Woolworths showed a similar pattern that morning. Its own 1.5L bottle and its 24 pack of 600mL bottles both read 7 cents per 100mL, its 4L bottle read 9 cents, and its 6 pack of 1.5L bottles read 6 cents.

So the answer changes with the pack. A multipack of the bigger bottles often comes out lowest, but read the number on the day you shop. Then think about the practical side: a cask is heavy, and a 24 pack takes up a lot of room in the cupboard.

1. Check the unit price on every size.
2. Multipacks of big bottles often win, but not always.
3. Buy a size you can carry and store.

House brand vs name brand bottled water

For plain still water, many shoppers are happy with the house brand, and the unit price gap with the big names can be wide. On 17 October 2026 at Coles, the name brand 1.5L bottle cost more than three times as much per 100mL as the Coles 1.5L bottle.

If your household prefers a particular brand, that is fine. Just compare it on the number. Name brand water goes on special from time to time, and a special can close some of the gap. Open Today's deals to see what is on special now with the was price beside it, then check the unit price against the house brand before you buy.

When you find the water you like at the right price, save it as a favourite so you can reopen it fast next time.

• Compare house brand and name brand on the unit price.
• A special can narrow the gap, so check the number.
• Favourite the one you buy.

Has bottled water gone up? Check the price history

In October, news reports said Woolworths had lifted its own brand 1.5L spring water from 80 cents to a dollar, in line with Coles. In Discount Trolley price history, both house brand 1.5L bottles showed 80 cents at times earlier this year, and both read a dollar when we checked on 17 October 2026.

A move like that is easy to miss on a cheap item, and it adds up if you buy water every week. Open the product in Discount Trolley and look at the price history to see how the price has moved. Dete, our koala, reads that history and holds up one sign: Good time, Wait if you can or About usual. When there is not enough history yet, the sign says Not sure yet. Tap the sign to see the chart.

Water does not go off fast, so a real low is a fair time to buy a pack or two ahead. For more on judging a deal, read how to spot a fake supermarket special and when a bulk buy grocery deal is worth it.

• Small price moves add up on weekly buys.
• Price history shows how the price has moved.
• Stock up on a real low, not on a loud tag.

Compare bottled water across stores on one list

Water usually goes in the same trip as the milk, bread and fruit, so it belongs on the same list. Add the water you want to My List in Discount Trolley, and the list shows a count for each store so you can see where your lines sit before you leave.

To check the same product at other stores, open the product page and scroll to Compare Stores. It shows the same product at other stores where data is available, and it tells you plainly when a product is not stocked somewhere, so you do not make a wasted trip.

For the habit on any staple, read how to use unit prices to find the cheapest groceries. For the milk that goes in the same trolley, see compare milk prices on one list. To weigh a second stop, read should you split your grocery shop across two stores.

• One list for water and the rest of the shop.
• Compare Stores for the same product at other stores.
• Check while you have signal, then shop the list.

What Discount Trolley does (and does not) claim about bottled water

Discount Trolley helps you check the grocery price information that is available for the water on your list. It does not promise savings, crown one brand or store as the cheapest forever, or carry the full range at all stores. Prices and specials change, so check again on the day you shop.

Woolworths, Coles, ALDI, IGA, Harris Farm, Priceline and Chemist Warehouse where data is available. Not affiliated with those stores. The shelf can differ from the screen. Live prices need a connection.

For more unit price comparisons, see breakfast cereal price comparison Australia, laundry detergent price comparison Australia, toilet paper price comparison Australia and coffee beans price comparison Australia.

• No invented savings or rankings.
• No forever cheapest brand or store.
• No affiliation with the supermarket chains.

Questions shoppers still ask