Calcylator
Kilowatts to Watts

Kilowatts to watts:
multiply by 1,000

Convert kilowatts to watts for heaters, motors, chargers and solar panels, with a chart and the kW versus kWh mix-up.

Calcylator Editorial Team

Updated · 5 min read

How many watts are in a kilowatt?

One kilowatt is exactly 1,000 watts. The prefix kilo means one thousand, so no rounding or special factor is involved. Converting kW to watts only means moving the decimal point three places to the right.

The watt measures power, which is how fast energy is used or produced. Small devices such as phone chargers and light bulbs are rated in watts, while larger machines, heaters and home solar systems are rated in kilowatts.

The kW to watts formula

Kilowatts to watts =watts = kW × 1000
watts:
power in watts (W)
kW:
power in kilowatts
1000:
watts in one kilowatt (exact)
To go the other way, divide: kW = watts ÷ 1000.

  • Heater rating

    3.5 kW

  • Multiply

    3.5 × 1000

Power in watts

3,500 W

On a 230 volt supply this heater draws about 15.2 amps, because current is watts divided by volts.

A second example uses solar panels. A rooftop system of 12 panels rated at 400 W each produces 4,800 W at its peak, which is 4.8 kW. To compare it with a 5 kW inverter, you can state both in kW or both in watts.

Chart: kW to watts

Kilowatts to watts
Kilowatts (kW)Watts (W)
1 kW1000 W
2 kW2000 W
5 kW5000 W
10 kW10000 W
25 kW25000 W
50 kW50000 W
100 kW100000 W
250 kW250000 W
500 kW500000 W
1000 kW1000000 W

To use the chart for other values, shift the decimal. 7 kW is 7,000 W, and 0.25 kW is 250 W. For 12 kW add 10 kW and 2 kW, which is 10,000 + 2,000 = 12,000 W.

Where kW to watts is used

  • Home heaters and air conditioners: ratings in kW must be compared with the watts shown on a plug or circuit breaker label.
  • Electric vehicle chargers: a home charger rated at 7 kW delivers 7,000 W.
  • Solar panels and inverters: panels are sold in watts while inverters are often sold in kW.
  • Generators: a 5 kW generator can run loads up to 5,000 W in total, so adding up your appliances in watts shows whether it is large enough.

Do not confuse kW with kWh

The most common source of confusion is kilowatts versus kilowatt-hours. Your electricity meter and bill count kilowatt-hours, which is energy. A 1 kW heater running for one hour uses 1 kWh. Running it for 5 hours uses 5 kWh. The kW figure only tells you how fast the heater uses energy.

Converting kW to watts is therefore only one step. To work out cost, convert to kWh by multiplying the power in kW by the hours of use, then multiply by the price per kWh.

A short sizing check for a circuit

A 3 kW electric shower or heater is 3,000 W. At 230 volts it draws 3,000 ÷ 230 = 13.04 amps, so it needs a circuit built for at least that current. This shows why converting to watts first is useful: formulas for current, voltage and resistance all use watts, not kilowatts. Always convert before substituting a rating into a formula.

Common mistakes with kW and watts

  • Moving the decimal the wrong way. A figure in watts is always 1,000 times the figure in kW, so 2 kW cannot be 0.002 W.
  • Writing the symbol wrongly. The correct symbols are kW for kilowatts and W for watts, and a capital K means something else.
  • Mixing power and energy, for example giving a battery size in kW when the correct unit is kWh.
  • Mixing up MW and kW. A megawatt is 1,000 kW, so 1 MW is 1,000,000 W.

Common questions

How many watts are in a kilowatt?

There are exactly 1,000 watts in one kilowatt. The prefix kilo means one thousand, so the conversion never changes. A 2 kW heater is therefore a 2,000 W heater, and a 0.5 kW motor is 500 watts.

How do I convert kW to watts?

Multiply the kilowatts by 1,000, which moves the decimal point three places to the right. For example, 3.5 kW is 3.5 × 1,000 = 3,500 W. A figure such as 0.75 kW becomes 750 W.

Is a kilowatt the same as a kilowatt-hour?

No. A kilowatt (kW) measures power, the rate of using energy at a moment. A kilowatt-hour (kWh) measures energy used over time. A 2 kW heater running for 3 hours uses 6 kWh, which is what an electricity bill charges.

How do I convert watts to kW?

Divide the watts by 1,000, which moves the decimal point three places to the left. For example, 1,500 W is 1.5 kW, and 60 W is 0.06 kW. The kW number is always smaller than the watts number.

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