Why the saving isn't the same for every machine
Most Australian washing machines only connect to a cold tap and heat their own water internally for a warm or hot program. Switching to cold skips that heating step entirely, the single part of the cycle that uses most of the electricity. Sustainability Victoria puts a figure on that step directly: “80–90% of the energy used by a washing machine goes toward heating the water”, which is also why the cold-wash energy figure on an Energy Rating Label, where a manufacturer chooses to publish one, is voluntary rather than mandatory. The label's main kWh-per-year number, the one our calculator's own registry medians use, is always the warm-wash test result, confirmed separately by CSIRO's Australian Housing Data: only the warm-wash figure is compulsory, so “the Star Rating relates only to the warm-wash figure, not to cold.”
How much that internal heating step actually costs isn't a flat number either. YourHome, the Australian Government's own sustainable-housing guide, publishes loader-specific figures rather than one rule for every machine: “washing in warm or hot water uses approximately 50% to 85% more energy than washing in cold water, depending on whether you have a front loader (50%) or top loader (85%) washing machine.” Applied to the same registry medians our washing machine calculator already uses (0.73 kWh warm for a front loader, 1.15 kWh warm for a top loader), a cold wash works out to roughly 0.49 kWh and 0.62 kWh respectively, a 33% saving on a front loader and 46% on a top loader. Both are real money, and neither figure is the flat “half” that general advice, including our own calculator's FAQ below, tends to round to.
Worked example, NSW: a front loader runs about 24¢ a load warm against 16¢ cold; a top loader about 37¢ warm against 20¢ cold. At 5 loads a week, the table below has the full-year saving in every state.
What this costs, state by state
The annual saving from switching every load to cold, at the calculator's own default of 5 loads a week, using YourHome's loader-specific percentages applied to the same registry medians (0.73 kWh front, 1.15 kWh top) our calculator already uses.
| State | Rate | Front loader, warm to cold | Top loader, warm to cold |
|---|---|---|---|
| New South Wales | 32.4¢ | $20.27 | $44.77 |
| Victoria | 29.8¢ | $18.65 | $41.17 |
| Queensland | 31.2¢ | $19.52 | $43.11 |
| South Australia | 38.1¢ | $23.84 | $52.64 |
| Western Australia | 33.6¢ | $21.02 | $46.43 |
| Tasmania | 28.9¢ | $18.08 | $39.93 |
| Australian Capital Territory | 27.4¢ | $17.14 | $37.86 |
| Northern Territory | 31.7¢ | $19.83 | $43.80 |
Reference rates for 2026–27. Your row is highlighted once you set your location.
What this means for the "just wash cold" advice
The saving is real in every state and for both loader types, so switching to cold is worth doing regardless of what machine is in the laundry. But the size of that saving is worth knowing accurately rather than rounding to "half", especially for a front loader: a 33% cut is still the single biggest lever a front-loader household has over the running cost this site's calculator prices, just not quite the 50% the loosest version of the advice implies. It matters more for a top loader, where the 46% figure is close enough to half that the rounded advice holds up fairly well.
There's one case where none of this applies: a machine plumbed into both a hot and cold tap, connected to a genuinely cheap-to-run hot water source such as solar or an efficient heat pump system, can heat its warm wash from that external supply instead of its own internal element. CSIRO's own housing data notes this bypasses the machine's internal heater entirely, so a dual-connected machine on the right hot water system "uses about the same energy to do a warm wash as it would a cold wash," the one real exception to the numbers above.
Common questions
Does a cold wash really cost half as much as a warm wash?
Not quite, and it depends on the machine. The Australian Government's own YourHome guide puts the real gap at 50% more for a front loader and 85% more for a top loader when washing warm instead of cold, so a front loader saves about a third switching to cold, a top loader closer to half.
Why does the saving depend on whether it's a front loader or top loader?
Most machines heat their own wash water internally from a cold-only connection, and that heating step is 80 to 90% of the total energy used, Sustainability Victoria's own figure. A front loader is already more efficient overall, so the same heating step is a smaller share of a smaller total; a top loader's higher overall energy use means the identical heating step accounts for more of the bill, which is why its percentage gap between warm and cold runs higher.
Is the kWh figure on a washing machine's Energy Rating Label a cold-wash or warm-wash number?
It's the warm-wash figure. That's the only test the label is required to publish; a cold-wash number only appears if the manufacturer chooses to add it, per CSIRO's Australian Housing Data. The registry medians our washing machine cost per load calculator uses are the same mandatory warm-wash figures.
Does a higher star rating still matter if I always wash cold?
Yes, though the gap it measures is a warm-wash gap. Our star rating guide finds two real 8kg front loaders in the same government registry four times apart on running cost, all on the mandatory warm-wash test this page's own figures also come from, so a more efficient machine still washes a cold load cheaper too, even though cold isn't what the star count directly measures.
Sources
Loader-specific warm-vs-cold energy gap (50% front loader, 85% top loader), quoted directly: YourHome, Appliances and technology, the Australian Government's guide to environmentally sustainable homes. Corroborating "80–90% of energy goes toward heating the water" figure: Sustainability Victoria, Reduce washing machine costs at home. Confirmation that the mandatory Energy Rating Label figure is a warm-wash-only test, and the dual-connection exception: CSIRO, Australian Housing Data, Appliances. General mechanism ("heating water is by far the biggest user of energy when washing fabric"): energy.gov.au, Appliances. Registry medians for a front and top loader (0.73 kWh, 1.15 kWh): the same energyrating.gov.au registration database (July 2026 snapshot) our washing machine cost per load calculator uses. Electricity rates: AER Default Market Offer and each state's regulated reference tariff, current for 2026–27. All fetched July 2026.