Electricity cost calculator
Calculator
The calculator needs JavaScript. The tables below give the same numbers for common cases.
How it is worked out
- kWh = watts × hours ÷ 1,000 = 0.5 per day.
- Cost = kWh × price per kWh. Your price is on your electricity bill; it differs by place and time of day.
| Inputs | Answer |
|---|---|
| Device power: 100; Hours used per day: 5; Price per kWh: 0.16 | 100 W for 5 hours a day uses 0.5 kWh a day and costs $0.08 a day, $29.20 a year at $0.16 per kWh. |
| Device power: 1500; Hours used per day: 2; Price per kWh: 0.2 | 1,500 W for 2 hours a day uses 3 kWh a day and costs $0.60 a day, $219.00 a year at $0.20 per kWh. |
| Device power: 60; Hours used per day: 24; Price per kWh: 0.12 | 60 W for 24 hours a day uses 1.44 kWh a day and costs $0.17 a day, $63.07 a year at $0.12 per kWh. |
How to use it
Energy in kilowatt-hours is watts × hours ÷ 1,000. A 100 W device used 5 hours a day uses 0.5 kWh a day; at $0.16 per kWh that is $0.08 a day, about $2.43 a month and $29.20 a year. Your price per kWh is on your electricity bill and differs by place and time of day.
For devices that cycle on and off, such as refrigerators, use the average power or the hours it actually runs.
Frequently asked questions
How do I calculate what a device costs to run?
kWh per day × price per kWh.
What is a kWh?
The energy used by a 1,000 watt device running for one hour.
Where do I find my price?
On your electricity bill.
Method: standard arithmetic shown step by step; no outside data is used. Checked 2026-11-12.
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General information only. Results are plain arithmetic on the numbers you enter; check anything important (money, health, school work) against your own records or the official source.