Volts to Watts Calculator
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Energy
kWh Cost Calculator
Find the energy and cost to run any appliance.
Monthly cost
—
To run it.
| Daily energy | — |
|---|---|
| Monthly energy | — |
| Yearly cost | — |
| Power | — |
Show our math
Enter your figures above to see the step-by-step working.
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How the kWh Cost Calculator Works
An appliance’s running cost comes from its power (watts), how long it runs, and your electricity rate. Convert watts to kilowatts (divide by 1,000), multiply by hours of use to get kilowatt-hours, then multiply by your cost per kWh. A 1,000-watt heater run 3 hours a day uses 3 kWh daily — about $13.70 a month at 15¢/kWh.
kWh is energy (power over time); it’s what your utility bills you for. Cutting either the wattage or the hours cuts the cost proportionally.
cost = watts ÷ 1000 × hours × rate per kWh
Frequently Asked Questions
How do I calculate the cost to run an appliance?
Multiply its kilowatts by the hours used, then by your electricity rate. A 1 kW device for 3 hours is 3 kWh.
What is a kilowatt-hour?
The energy of running 1,000 watts for one hour — the unit your electric bill charges by.
How much does it cost to run a 1500W heater?
At 15¢/kWh, about 22.5¢ per hour, or roughly $1.80 for 8 hours.
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