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Electricity Calculator
Electricity Calculator
Electrical energy, cost, charge, and capacitance calculations
E = P × t | Q = I × t | Cost = kWh × rate
W
hours
Result
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Stat 1
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Stat 2
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Stat 3
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Step-by-Step
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About the Electricity Calculator
Estimate energy use, running cost and electric charge for an appliance from its power rating and how long it runs.
How to use the Electricity Calculator
- Choose Electric Energy, Energy Cost or Electric Charge.
- Enter the Power (P) in watts, Time or Usage per Day and the Electricity Rate per kWh (or the Current (I) for charge).
- Press Calculate.
Formula and method
Energy (kWh) = Power (kW) × Time (h), Cost = Energy × Rate and Charge (C) = Current (A) × Time (s).
Worked example
A 1,500 W heater running 3 hours uses 4.5 kWh. At $0.12 per kWh that costs $0.54.
Tips
- Standby power adds up. Switch off devices you are not using.
- Look for the wattage on the appliance label.
Frequently Asked Questions
It is printed on your bill, usually in cents or pence per kWh.