What Is the kW to kWh Calculator?
This tool converts power measured in kilowatts (kW) into energy measured in kilowatt-hours (kWh). Power is the rate at which energy is used at any instant, while energy is the total amount consumed over a period of time. A 1 kW appliance running for 1 hour uses exactly 1 kWh of energy — the unit your electricity bill is based on.
How to Use It
Enter the device's power rating in kilowatts and the number of hours it runs. The calculator multiplies the two values to return total energy in kWh, plus the equivalent in watt-hours (Wh). If your appliance is rated in watts, divide by 1,000 first (e.g. 1,500 W = 1.5 kW).
The Formula Explained
The relationship is simply $$\text{Energy (kWh)} = \text{Power (kW)} \times \text{Time (h)}$$ Because a kilowatt is 1,000 watts and a kilowatt-hour is the energy of 1,000 watts sustained for one hour, multiplying power by time directly yields energy. To convert to watt-hours, multiply the kWh result by 1,000.
Worked Example
Suppose a 5 kW electric heater runs for 3 hours. Energy used $$= 5 \times 3 = \textbf{15 kWh}$$ (or 15,000 Wh). At an electricity price of $0.20 per kWh, that session would cost \(15 \times \$0.20 = \$3.00\).
FAQ
Is kW the same as kWh? No. kW measures instantaneous power; kWh measures energy used over time. They are related by the running duration.
How do I convert watts to kW? Divide watts by 1,000. A 750 W device equals 0.75 kW.
Can I use minutes instead of hours? Convert minutes to hours first (divide by 60), then enter the result in the hours field.
