Watts to Kilowatts Calculator
A watt is a unit of power. A kilowatt is 1,000 watts: "kilo" always means times 1,000, the same as kilometers or kilograms. Appliance labels are usually stamped in watts. Bills, breakers and most calculators on this site work in kilowatts. Converting between them is usually the first step.
A 1,500 W space heater, for example, is a 1.5 kW load. Enter any wattage below to see the same math.
kW = 1500 / 1000 = 1.500 kW
That kilowatt figure is also the number worth writing down before checking a bill. A rate charged in cents per kilowatt-hour needs a kilowatt starting point, not a watt one, so this conversion is normally the very first step in estimating what a device adds to a monthly total.
The conversion
Watts and kilowatts measure the same thing at different scales, so there is only one formula, not a different one for each direction. Divide by 1,000 to go from watts to kilowatts; multiply by 1,000 to go the other way.
Worked example: a 1,500 W space heater. 1500 / 1000 = 1.5 kW. The same division works for a 60 W bulb or a 5,000 W sub-panel load: the arithmetic doesn't change with the size of the device, and the result reads the same whether the wattage came from a nameplate, a spec sheet, or a box on a store shelf.
The conversion matters because almost everything downstream of a wattage label is expressed in kilowatts, not watts: a monthly bill, a breaker size, a generator sizing chart. A 1,500 W heater and a 1.5 kW heater are the exact same appliance; only the unit written on the box changed.
Unlike converting kilowatts to amps or to horsepower, this one doesn't depend on voltage, power factor, or anything else about the circuit. Watts and kilowatts are the same unit at two different scales, so the number in, the number out, and the 1,000 in between are the whole calculation.
Common household wattages, watts to kilowatts
A quick reference for the wattage figures printed on typical device labels, from small electronics near the top to heating appliances near the bottom. Actual nameplate wattage varies by model and by setting, so check the label on hand rather than assuming a device matches the table exactly.
| Watts | Kilowatts |
|---|---|
| 60 W | 0.06 kW |
| 100 W | 0.1 kW |
| 300 W | 0.3 kW |
| 750 W | 0.75 kW |
| 1500 W | 1.5 kW |
| 2000 W | 2 kW |
| 3000 W | 3 kW |
| 5000 W | 5 kW |
What to work out next from kilowatts
Questions
Watts to kilowatts FAQ
Short answers to the questions that come up once a wattage label needs to turn into a kilowatt figure.
Do milliwatts and megawatts follow the same factor-of-1,000 pattern?
Yes: every step between the metric power prefixes is a factor of 1,000, in both directions. 1,000 milliwatts make 1 watt, 1,000 watts make 1 kilowatt, and 1,000 kilowatts make 1 megawatt. A 1,500 W space heater is also 1,500,000 mW or 0.0015 MW, the same figure, just shifted along the same scale.
Why do appliance labels use watts but electricity bills use kilowatt-hours?
Watts measure a rate, how fast a device is using power right now, while kilowatt-hours measure energy used over time. A bill needs the second figure, since cost depends on how long something runs, not just how powerful it is. Getting from a label to a bill takes two steps: divide the watts by 1,000 for kilowatts, then multiply by the hours run for kilowatt-hours.
Is a device’s rated wattage what it draws all the time?
Not usually. The number on the label is typically a maximum, not a constant draw. A "1,500 W" space heater only pulls the full 1,500 W on its highest setting; a lower setting or a thermostat cycling it off draws less. Refrigerators, air conditioners and anything with a compressor behave the same way, cycling between a running wattage and near zero.
Does converting watts to kilowatts need the voltage or current?
No: watts and kilowatts measure the same quantity, so moving between them is a straight division by 1,000, nothing else. That is different from a conversion like kilowatts to amps, which needs voltage and power factor because it is crossing from power into current.
Why do some appliances list two wattage numbers, like "1500W / 900W"?
That is usually a high and a low setting, not a single fixed draw. A space heater or hair dryer with two power levels draws less current, and costs less to run per hour, on the lower number. Converting each setting to kilowatts separately (1500 W → 1.5 kW, 900 W → 0.9 kW) gives the real range of what the device can pull.