Our power cost calculator estimates any electrical appliance's total energy usage (in kWh) and annual running cost (in dollars).
Want to skip the maths lesson? Use a plug-in power meter instead.
How to Use Our Electricity Cost Calculator
All you need to enter is the following:
1) Power Draw - How much power the appliance uses in Watts. You can find this on most compliance plates, as pictured here.
2) Your Electricity Tariff in cents per kWh. You can find this on your electricity bill. Enter 30 if you don't have one handy.
3) An estimate of how often you use the appliance in hours per day, days per week, and weeks per year.
Appliance Electricity Cost & kWh Calculator:
- Adjust the sliders for your appliance's power draw, electricity tariff, and typical usage pattern.
- The results table updates automatically as you adjust the values.
| Input | Value |
|---|---|
|
250 Watts |
|
|
35 cents/kWh |
|
|
8 hours per day |
|
|
5 days per week |
|
|
50 weeks per year |
| Results | Per Day | Per Year |
|---|---|---|
| Electricity Usage: | 0 kWh | 0 kWh |
| Running Cost: | $0 | $0 |
Note: our affordable power meters do some of these calculations for you.
Example Appliance Energy Cost Calculations
Here are some example calculations for everyday appliances. Enter them in our calculator above, change the inputs, and see the impact. These examples assume an electricity tariff of 30 cents per kWh.
| Appliance | Usage | Annual Cost |
| Kettle (2,200W) | 0.1h/day | $24 |
| Pool Pump (1,200W) | 8h/day | $1048 |
| Fridge / Freezer (140W) | 10h/day | $153 |
| Halogen Downlight (65W*) | 6h/day | $43 |
| LED Downlight (10W) | 6h/day | $7 |
| TV (100W on) | 5h/day | $55 |
| TV (5W in standby) | 19h/day | $10 |
| Ducted Air Con (4,500W) | 6h/day, 24wk/yr | $1361 |
| Split System AC (1,100W) | 6h/day, 24wk/yr | $333 |
| Efficient Ceiling Fan (15W) | 8h/day, 24wk/yr | $6 |
| Clothes Dryer (2400W) | 6h/wk, 50wk/yr | $216 |
| Fan Heater (1800W) | 4h/day, 12wk/yr | $181 |
| Foot Mat Heater (90W) | 6h/day, 12wk/yr | $14 |
| Electric Stove on Simmer (600W) | 1h/day, 5day/wk | $47 |
| Billyboil Thermal Cooker (0W**) | 1h/day, 5day/wk | $0 |
* A 50W halogen light bulb loses an extra 15W in the transformer. It's a loss that goes down to just one or 2W when you switch to an LED MR16 light bulb.
** Keeps food hot enough inside to continue cooking for hours without additional power.
How to Calculate Electricity Usage Costs
Our power calculator uses a simple formula to calculate annual energy usage and costs. Here's how it works:
Electricity Usage Per Year = (Watts / 1000) * Hours/Day * Days/Week * Weeks/Year = kWh/year
Electricity Cost Per Year = kWh/year * (cents/kWh / 100) = $/year
The daily figures in the results table only apply to the days when the appliance is used.
More Accurate & Easier Ways To Calculate Your Electricity Costs
The above electricity usage calculator is quick, free, and easy to use. However, it also has low accuracy because it relies on estimates and cannot log actual energy usage over time. As the saying goes: garbage in, garbage out - so please be careful when entering your data!
For this reason, we sell several devices to help you calculate the cost of running your appliances with much greater ease and accuracy. Here are the two main types:
The Reduction Revolution Power Meter is one of our most popular products. It calculates instantaneous power usage (Watts), energy usage (kWh over time), cost, and more.
Our range of Wireless Energy Monitors takes things a step further. They monitor your entire household's energy usage from one device.
Tips When Calculating Appliance Running Costs
Our electricity cost calculator on this page is ideal for appliances with a constant power draw. Examples include LED light bulbs, most heaters, pumps, motors, and portable fans.
Many appliances are switched on 24/7 but only draw power some of the time. For example, a refrigerator's compressor may only draw power for 8 to 12 hours per day. You can either estimate this based on observations or use a plug-in power meter.
For other appliances, the power usage can vary significantly. For example, a dishwasher may use 2400W when heating, 50W when pumping water, and 5W on standby. Estimating an 'average power' for these appliances can be tricky. You are best off checking any device that goes through a 'cycle' with a power meter.
It's easiest to calculate energy usage in terms of 'days per week' and 'weeks per year' rather than 'days per year' or 'hours or year'. Strictly speaking, there are 52 weeks and one day in a non-leap year. Our calculator ignores this and bases a year on 52 weeks (364 days). For example, many devices operate for five days per week, and you take a holiday for a few weeks per year.
