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Convert Kilocalories to Watt-hours

1 kilocalorie is 1.162222 Wh. One kilocalorie is exactly 1.16222222222 watt-hours.

One kilocalorie is 1.1622222 watt-hours. To convert kilocalories to watt-hours, multiply by 1.1622222; to go the other way, divide by 1.1622222 or multiply by 0.86042065. The factor is exact rather than rounded: it follows from NIST Special Publication 811. A thousand small calories, and what a food label means by "Calories" with a capital C.

Factor checked against the defining standard · How we check

Watt-hours
1.162222 Wh
Kilocalories × 1.1622222
value * 1.162222222221.162 Wh

1 kilocalorie in every energy unit

UnitValueExact factor
joules4,184 J× 4,184
kilojoules4.184 kJ× 4.184
calories1,000 cal× 1,000
kilocalories (as entered)1 kcal
watt-hours1.162222222 Wh× 1.16222222222
kilowatt-hours0.001162222222 kWh× 0.00116222222222
British thermal units3.965666831 BTU× 3.96566683139
foot-pounds3,085.960033 ft·lbf× 3,085.96003258

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 kilocalories to watt-hours?

  1. 1.Take the measurement in kilocalories.
  2. 2.Multiply by 1.1622222 — that is how many watt-hours fit in one kilocalorie.
  3. 3.To go back the other way, divide by 1.1622222, or multiply by 0.86042065.

Worked example: 25 kilocalories to watt-hours

Formula
kcal × 1.1622222 = Wh
Arithmetic
25 × 1.1622222 = 29.055556 Wh
Answer
25 kcal = 29.055556 Wh

The factor is rounded for display; the figure above is computed from the full value.

Kilocalories to watt-hours conversion table

KilocaloriesWatt-hours
1 kcal1.162222 Wh
2 kcal2.324444 Wh
3 kcal3.486667 Wh
4 kcal4.648889 Wh
5 kcal5.811111 Wh
6 kcal6.973333 Wh
7 kcal8.135556 Wh
8 kcal9.297778 Wh
9 kcal10.46 Wh
10 kcal11.622222 Wh
12 kcal13.946667 Wh
15 kcal17.433333 Wh
20 kcal23.244444 Wh
25 kcal29.055556 Wh
50 kcal58.111111 Wh
100 kcal116.222222 Wh
200 kcal232.444444 Wh
300 kcal348.666667 Wh
500 kcal581.111111 Wh
1000 kcal1,162.222222 Wh
2000 kcal2,324.444444 Wh
5000 kcal5,811.111111 Wh
10000 kcal11,622.222222 Wh

What is a kilocalorie?

A thousand small calories, and what a food label means by "Calories" with a capital C. A 2,000 calorie diet is 2,000 kcal, or 8.4 megajoules.

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 kilocalorie?

One kilocalorie is 1.1622222 watt-hours. Going the other way, one watt-hour is 0.86042065 kilocalories. 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 kilocalorie?
1.1622222. 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 kilocalories?
Divide by 1.1622222, or multiply by 0.86042065 — they are the same operation.

Other energy conversions

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

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