One kilowatt hour is the energy a 1000 W appliance uses in one hour. An 800 W induction hob for an hour is 0.8 kWh; a 2000 W water heater for thirty minutes is also 1 kWh.

Is an air conditioner's stated wattage what it actually draws?

Not exactly. An inverter unit's label is usually rated input power, and real consumption varies around it with room temperature and settings — higher on start-up, lower once stable. The estimate here assumes constant power, so treat it as an upper bound.

UNIT CONVERSION · CALCULATED FROM DEFINITIONS

Watts to Kilowatts Converter

Convert power units and estimate monthly electricity use in kWh.

From

FormulakW = W × 0.001

Ratio1 W = 0.001 kW

Hours used per day

Estimated monthly use0.24 kWh

Estimated as constant power multiplied by hours, so treat it as an upper bound. Real use is usually lower, and this is not an electricity bill.

Every unit in this category

kW0.001Kilowatt

MW0.000001Megawatt

PS0.001359622Metric horsepower

hp0.001341022Mechanical horsepower

Common values

W	kW
`0.5 W`	`0.0005 kW`
`1 W`	`0.001 kW`
`2 W`	`0.002 kW`
`3 W`	`0.003 kW`
`5 W`	`0.005 kW`
`10 W`	`0.01 kW`
`15 W`	`0.015 kW`
`20 W`	`0.02 kW`
`25 W`	`0.025 kW`
`30 W`	`0.03 kW`
`50 W`	`0.05 kW`
`75 W`	`0.075 kW`
`100 W`	`0.1 kW`
`150 W`	`0.15 kW`
`200 W`	`0.2 kW`
`500 W`	`0.5 kW`
`1000 W`	`1 kW`

About this tool

Enter watts to get kilowatts, along with horsepower and the other power units. Power (W, kW) and consumption (kWh) are different things: power is the rate of use right now, and kWh is power multiplied by time. An estimate field takes hours per day and works out roughly how many kWh a month that becomes, which is useful for sizing air conditioning or a water heater — but it is an estimate, not a bill.

How it works

Enter a figure in watts, or use kilowatts or horsepower instead.
Read the other power units.
Enter hours per day to estimate monthly kWh.

Precision and definitions

A kWh is energy rather than power and needs a duration. The estimate here is not an electricity bill.

Privacy

Every conversion runs inside this browser. The values you enter are never uploaded, stored, or written to the URL or any log.

Frequently asked questions

What is one kWh?: One kilowatt hour is the energy a 1000 W appliance uses in one hour. An 800 W induction hob for an hour is 0.8 kWh; a 2000 W water heater for thirty minutes is also 1 kWh.
Is an air conditioner's stated wattage what it actually draws?: Not exactly. An inverter unit's label is usually rated input power, and real consumption varies around it with room temperature and settings — higher on start-up, lower once stable. The estimate here assumes constant power, so treat it as an upper bound.

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