Appliance Energy Cost Calculator
Running cost of an appliance, or up to five, from watts, hours a day, days a week and your rate: cost per hour, per day, per average month and per year. How it works
Use the Appliance Energy Cost Calculator
About the Appliance Energy Cost Calculator
A 100 W device running 8 hours a day at $0.15 per kWh uses 0.8 kWh a day and costs $0.12 a day, $3.65 for an average month and $43.83 for an average year, or $0.015 per hour of use. The formula is watts × hours ÷ 1,000 × rate, and the rate is the one you enter.
Cost by power at 4 hours a day and $0.15 per kWh
| Power | Per hour of use | kWh per day | Per day | Per month | Per year |
|---|---|---|---|---|---|
| 10 W | $0.002 | 0.04 | $0.01 | $0.18 | $2.19 |
| 60 W | $0.009 | 0.24 | $0.04 | $1.10 | $13.15 |
| 100 W | $0.015 | 0.40 | $0.06 | $1.83 | $21.91 |
| 500 W | $0.075 | 2.00 | $0.30 | $9.13 | $109.58 |
| 1,000 W | $0.150 | 4.00 | $0.60 | $18.26 | $219.15 |
| 1,500 W | $0.225 | 6.00 | $0.90 | $27.40 | $328.72 |
Month = 30.44 days and year = 365.25 days. The rate of $0.15 per kWh is an example, not a local price.
How to use this tool
- Type the appliance’s power in watts. A plug-in watt meter gives the average draw; the label figure is the maximum and overstates a fridge or a thermostat heater.
- Type the hours it runs per day, up to 24.
- Type the price per kWh from your electricity bill, and the days a week it runs if not every day.
- Press Add another appliance to price up to five together, each with its own watts and hours.
- Read the cost per hour, per day, per average month and per average year.
Frequently asked questions
- How do I calculate the cost of running an appliance?
- Multiply watts by hours of use and divide by 1,000 to get kWh, then multiply by your price per kWh. A 100 W device for 8 hours is 0.8 kWh, and at $0.15 per kWh it costs $0.12.
- How much does it cost per hour to run a 1,000 watt appliance?
- At $0.15 per kWh, $0.15 per hour of use, since 1,000 W is 1 kWh each hour. At $0.30 per kWh it would be $0.30. The tool shows this line to three decimals.
- What electricity rate should I enter?
- The price per kWh on your bill, in any currency: the results come out in the same currency, though they are shown with a $ sign. Fixed charges, taxes, demand charges and time-of-use rates are not included, so on a time-of-use plan enter the rate for the hours the appliance runs.
- Why is a month 30.44 days and a year 365.25?
- They are averages: 365.25 days is a year with leap days included and 30.44 is that year divided by 12. A 100 W device at 8 hours and $0.15 costs $3.65 for an average month and $43.83 for an average year. If it runs only on weekdays, set Days used per week to 5 and the year drops to $31.31; the daily figure stays the cost of a day of use.
- How much does a small device left on all day cost?
- A 5 W device running 24 hours a day uses 0.12 kWh. At $0.15 per kWh that is $0.02 a day and $6.57 for an average year.
- Can I add up the cost of several appliances?
- Yes, up to five. Each appliance adds its watts × hours ÷ 1,000 to the daily kWh, all at the same rate. A 100 W device for 8 hours plus a 1,000 W heater for 2 hours is 2.8 kWh a day: at $0.10 per kWh that is $0.28 a day and $102.27 a year. The per-hour line is the cost with every appliance on at once, $0.110 here.
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