How much does one degree of thermostat change cost?
By Sithum Imarsha Last reviewed
Government sources put it at 5 to 10% more energy a degree. On an example $600 heating season, 1°C warmer takes the bill to about $630 to $660. That is at least $30 more.
Your result
At least this much (conservative estimate)
$30a season
1°C warmer would cost you money. Government sources put this at 5 to 10% more energy a degree.
- Low end
- $30
- High end
- $60
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How we calculated this
Work out how many degrees you're changing
Heating: a warmer setpoint costs more. Cooling: a cooler setpoint costs more.
1°C warmer
Apply the range to your own running cost
Your typed cost × (1 + the percentage × degrees changed), once at 5% and once at 10%. We show the range, not one number, because the sources give a range, not one exact figure. A big enough drop stops the new cost at $0, never below.
$630 to $660 a season
The 5% to 10% for each degree is a rule of thumb (Official source). Source: energy.gov.au Heating and cooling (Wayback copy, 18 Sep 2026); YourHome Heating and cooling (Wayback copy, 29 Sep 2026).
A thermostat is a target, not a speed dial. Setting it further from the current temperature does not heat or cool the room any faster. An on/off unit runs at the same output either way, just for longer before switching off. Either way the room ends at the setpoint, and a setpoint further from the outside temperature just costs more to hold.
The real saving depends on your climate and how well insulated your home is. Someone already close to the recommended setpoint sees a smaller change than someone starting further off. This tool has no climate or insulation data, so it shows one flat range for everyone.
Sources
Questions
How much does one degree of thermostat change really cost?
Government sources put it at 5 to 10% more energy a degree (Official source). We show the full range rather than one number, because the sources give a range, not one exact figure.
Does turning the heater up higher warm the room faster?
No. A thermostat is a target temperature, not a speed control. An on/off heater runs at the same output either way, just for longer before it switches off. Either way the room ends at the setpoint, and a higher setpoint just costs more to hold. Our source is UK government energy advice. We found no Australian government page that says it, but the physics is the same here.
What temperature should I set my thermostat to?
We use 19°C for winter heating and 25.5°C for summer cooling (Estimate). Each is the middle of the ranges Australian sources give.
Does a fan help me raise the cooling setpoint?
Likely yes. Moving air makes a warm room feel cooler, so pairing a fan with air conditioning lets some people raise the setpoint comfortably. We found no Australian figure for how many degrees this is worth, so we do not put a number on it.
Why does this tool ask for my own running cost instead of working it out for me?
So it stays accurate to your actual heater or air conditioner, without guessing your fuel type or room size. Use the heater or air conditioner running cost calculator to get that number first, then bring it here.