Kilowatt-Hour Cost Calculator
Work out the running cost of any appliance in cents per hour or per use, based on its wattage and your electricity tariff.
Your results
Calculation breakdown
- Energy
- kWh = (watts / 1000) × hours used
- Cost
- Cost = kWh × usage rate (c/kWh) / 100
Worked example
A 2,000 W heater run for 2 hours a day at 32c/kWh uses 4 kWh a day, costing about $1.28 a day or around $467 a year.
Assumptions
- Uses a flat usage rate; time-of-use tariffs will change actual cost.
- Excludes daily supply charges and GST.
- Assumes constant power draw for the full period of use.
Sources
How this calculator works
This calculator converts an appliance's wattage into an estimated running cost using your own electricity usage rate. Enter the appliance's power draw in watts, how many hours it runs, and your per-kWh tariff to see the cost per use, per day and per year.
Frequently asked questions
How do I find an appliance's wattage?
Check the compliance plate or manual, usually on the back or base of the appliance, listed in watts (W) or kilowatts (kW).
Why does my bill not match this estimate?
Bills include supply charges, GST and other fees not captured by a single appliance's usage, and tariffs may vary by time of day.
Does standby power count?
No, this calculates active running cost only; use the Standby Power Cost calculator for appliances left plugged in.
Actual prices, usage, efficiency and savings vary by provider, equipment, location and behaviour.