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Kilocalories to Watt-hours Converter

Convert Kilocalories (kcal) to Watt-hours (Wh) instantly, or use the conversion table below to look up common values.

1 kcal = 1.162222 Wh

Kilocalories to Watt-hours conversion table

Kilocalories (kcal)Watt-hours (Wh)
11.162222
22.324444
33.486667
44.648889
55.811111
1011.622222
2529.055556
5058.111111
100116.222222

How to convert Kilocalories to Watt-hours

1 kcal equals 1.162222 Wh. Use the converter above for any value, or read the table for common conversions.

Wh = kcal × 1.1622222222222223 · kcal = Wh × 0.8604206500956023

Multiply a kilocalories figure by 1.162222 to get watt-hours, or divide it by 0.860421 to go the other way.

Worked examples

  • 1 kcal= 1.162222 Wh
  • 5 kcal= 5.811111 Wh
  • 10 kcal= 11.622222 Wh
  • 100 kcal= 116.222222 Wh
  • 500 kcal= 581.111111 Wh

What these units are

Kilocalories (kcal). A kilocalorie is 1,000 calories, or 4,184 joules. It is the 'calorie' on food labels, so a 2,000-calorie diet means 2,000 kilocalories.

Watt-hours (Wh). A watt-hour is the energy of one watt sustained for one hour — 3,600 joules. It is used for battery and power-bank capacity; a phone battery is typically 10 to 20 watt-hours.

All factors are exact definitions, so only the display is rounded.

Converting Kilocalories to Watt-hours in practice

Working in kilocalories

Exactly 1,000 thermochemical calories, or 4,184 joules, make one kilocalorie. A food label that prints calorie, often with a capital letter, means this unit rather than the small calorie of physics.

Food energy on packaging, diet plans, restaurant menus and sports nutrition is stated in kilocalories. Physiology and nutrition research also reports energy expenditure in the same unit.

Kilocalories convert to kilojoules by the exact factor 4.184, and to joules by 4,184, with no rounding. Since a kilowatt-hour is 3.6 megajoules, one kilocalorie is a little over 0.00116 kilowatt-hours.

The standard mistake is to treat the label's calorie as the small calorie and conclude that food holds far less energy than it does. The label unit is one thousand small calories.

The kilocalorie is the label unit, the calorie is its one-thousandth in physics, and the kilojoule is the metric equivalent at 4.184 kilojoules each. A diet figure and a physics figure therefore need different units before they can be compared.

Checking a kilocalories to watt-hours conversion

Energy units are defined against the joule, so every conversion in this dimension is a single exact multiplication by a published number rather than a chain of steps that could accumulate error.

The pair that needs care is the kilowatt-hour, because it looks like a power unit and is not. It is a watt sustained for an hour, which is why an electricity meter counts in kilowatt-hours while a generator is rated in kilowatts: one is an amount, the other is a rate, and only a duration links them.

To check an energy conversion, express both sides in joules or both in kilowatt-hours before comparing. The commonest mistake is treating a food calorie as a calorie when the label means a kilocalorie, which understates the figure a thousandfold.

Tanzania reference points

Real quantities, converted into the units on this page.

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