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Convert Kilowatt-hours to Watt-hours

1 kilowatt-hour is 1,000 Wh. One kilowatt-hour is exactly 1000 watt-hours.

One kilowatt-hour is 1000 watt-hours. To convert kilowatt-hours to watt-hours, multiply by 1000; to go the other way, divide by 1000 or multiply by 0.001. The factor is exact rather than rounded: it follows from NIST Special Publication 811. A thousand watt-hours, and the unit every electricity bill is added up in.

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Watt-hours
1,000 Wh
Kilowatt-hours × 1000
value * 10001,000 Wh

1 kilowatt-hour in every energy unit

UnitValueExact factor
joules3,600,000 J× 3,600,000
kilojoules3,600 kJ× 3,600
calories860,420.6501 cal× 860,420.650096
kilocalories860.4206501 kcal× 860.420650096
watt-hours1,000 Wh× 1,000
kilowatt-hours (as entered)1 kWh
British thermal units3,412.141633 BTU× 3,412.14163313
foot-pounds2,655,223.737 ft·lbf× 2,655,223.7374

Factors are entered by hand from NIST Special Publication 811 rather than derived from a units library, so the ones that terminate are exact rather than rounded.

How do you convert kilowatt-hours to watt-hours?

  1. 1.Take the measurement in kilowatt-hours.
  2. 2.Multiply by 1000 — that is how many watt-hours fit in one kilowatt-hour.
  3. 3.To go back the other way, divide by 1000, or multiply by 0.001.

Worked example: 25 kilowatt-hours to watt-hours

Formula
kWh × 1000 = Wh
Arithmetic
25 × 1000 = 25,000 Wh
Answer
25 kWh = 25,000 Wh

The factor is exact, so this figure is exact too — only the display is rounded.

Kilowatt-hours to watt-hours conversion table

Kilowatt-hoursWatt-hours
1 kWh1,000 Wh
2 kWh2,000 Wh
3 kWh3,000 Wh
4 kWh4,000 Wh
5 kWh5,000 Wh
6 kWh6,000 Wh
7 kWh7,000 Wh
8 kWh8,000 Wh
9 kWh9,000 Wh
10 kWh10,000 Wh
12 kWh12,000 Wh
15 kWh15,000 Wh
20 kWh20,000 Wh
25 kWh25,000 Wh
50 kWh50,000 Wh
100 kWh100,000 Wh
200 kWh200,000 Wh
300 kWh300,000 Wh
500 kWh500,000 Wh
1000 kWh1,000,000 Wh
2000 kWh2,000,000 Wh
5000 kWh5,000,000 Wh
10000 kWh10,000,000 Wh

What is a kilowatt-hour?

A thousand watt-hours, and the unit every electricity bill is added up in. Exactly 3.6 megajoules, and the reason a 100 W bulb left on for ten hours costs one unit.

What is a watt-hour?

One watt sustained for an hour, so exactly 3,600 joules. Battery capacity is quoted here because it is an amount of energy rather than a rate.

How many watt-hours are in a kilowatt-hour?

One kilowatt-hour is 1000 watt-hours, exactly. Going the other way, one watt-hour is 0.001 kilowatt-hours. Both figures come from the same defined relation rather than from a measurement, which is why they are the same today as they were in 1959.

Every energy unit here

UnitSymbolOne of these is
JoulesJthe base unit
KilojouleskJ1000 joule
Caloriescal4.184 joule
Kilocalorieskcal4184 joule
Watt-hoursWh3600 joule
Kilowatt-hourskWh3600000 joule
British thermal unitsBTU1055.0559 joule
Foot-poundsft·lbf1.3558179 joule

Source: NIST Special Publication 811 — the thermochemical calorie is exactly 4.184 J

Questions people actually ask

How many watt-hours are in a kilowatt-hour?
1000. One watt sustained for an hour, so exactly 3,600 joules. Battery capacity is quoted here because it is an amount of energy rather than a rate.
How do I convert watt-hours back to kilowatt-hours?
Divide by 1000, or multiply by 0.001 — they are the same operation.

Other energy conversions

Watt-hours to kilowatt-hours — the same conversion the other way.

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