Kilocalories Converter
Convert Kilocalories (kcal) to any other energy unit. The table below gives the exact figure for each unit, and every conversion is worked from the same engine as the converter.
What kilocalories convert to
One kcal in every other energy unit.
| Unit | 1 kcal | Reverse |
|---|---|---|
| Joules | 4,184 J | 2.3901e-4 kcal |
| Kilojoules | 4.184 kJ | 0.239006 kcal |
| Megajoules | 0.004184 MJ | 239.005736 kcal |
| Watt-hours | 1.162222 Wh | 0.860421 kcal |
| Kilowatt-hours | 0.001162 kWh | 860.42065 kcal |
| Calories | 1,000 cal | 0.001 kcal |
| BTU | 3.965667 BTU | 0.252164 kcal |
Multiply a kilocalories figure by the figure in the second column to get the unit in the first, or multiply by the third column to go the other way.
Kilocalories conversion reference
Kilocalories to Joules
One kilocalories is 4,184 joules, and one joules is 2.3901e-4 kilocalories.
The joule is the SI unit of energy: the work done by one newton over one meter. It is used for small energy amounts in physics and engineering.
- 1 kcal= 4,184 J
- 5 kcal= 20,920 J
- 10 kcal= 41,840 J
Energy in the International System of Units is measured in joules, where one joule is the work done by a force of one newton moving an object one metre. The symbol is J.
Physics and engineering use the joule for mechanical work, heat, radiation and electrical energy, and small appliance labels sometimes state a surge or pulse rating in joules.
Kilocalories to Kilojoules
One kilocalories is 4.184 kilojoules, and one kilojoules is 0.239006 kilocalories.
A kilojoule is 1,000 joules. It is used for food energy in most countries outside the United States, and for small industrial figures.
- 1 kcal= 4.184 kJ
- 5 kcal= 20.92 kJ
- 10 kcal= 41.84 kJ
One kilojoule is exactly 1,000 joules, and the symbol is kJ. It is the joule multiple that food packaging commonly prints, with energy shown in kilojoules beside kilocalories, and chemistry uses it for reaction energies.
Nutrition panels, exercise machines and dietary advice report energy in kilojoules wherever the metric system is used. Materials and fuel data, such as energy content per kilogram, are tabulated in kilojoules as well.
Kilocalories to Megajoules
One kilocalories is 0.004184 megajoules, and one megajoules is 239.005736 kilocalories.
A megajoule is 1,000 kilojoules, or about 0.278 kilowatt-hours. It is used for the energy content of fuels: a litre of diesel holds roughly 36 megajoules.
- 1 kcal= 0.004184 MJ
- 5 kcal= 0.02092 MJ
- 10 kcal= 0.04184 MJ
One megajoule is 1,000 kilojoules, which is one million joules. Fuels, industrial processes and large energy figures are quoted in megajoules when a count in joules would be unwieldy.
Fuel energy content, blast energy, industrial process heat and large-scale storage are described in megajoules. Engineering calculations for combustion and materials testing also use the unit.
Kilocalories to Watt-hours
One kilocalories is 1.162222 watt-hours, and one watt-hours is 0.860421 kilocalories.
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.
- 1 kcal= 1.162222 Wh
- 5 kcal= 5.811111 Wh
- 10 kcal= 11.622222 Wh
Kilocalories to Kilowatt-hours
One kilocalories is 0.001162 kilowatt-hours, and one kilowatt-hours is 860.42065 kilocalories.
A kilowatt-hour is 1,000 watt-hours, or 3.6 megajoules. It is the unit on electricity bills, and the 'unit' shown on a prepaid meter.
- 1 kcal= 0.001162 kWh
- 5 kcal= 0.005811 kWh
- 10 kcal= 0.011622 kWh
The kilowatt-hour is the energy of one kilowatt sustained for one hour, and it is exactly 3.6 megajoules. Its symbol is kWh, and it equals 1,000 watt-hours.
Electricity bills, prepaid meter units, solar generation totals and battery or power-bank capacity are all measured in kilowatt-hours. Appliance consumption over time is compared in the same unit.
Kilocalories to Calories
One kilocalories is 1,000 calories, and one calories is 0.001 kilocalories.
A calorie here is the small calorie of 4.184 joules — the energy needed to raise one gram of water by one degree Celsius. Food labels use the kilocalorie, which is 1,000 of these.
- 1 kcal= 1,000 cal
- 5 kcal= 5,000 cal
- 10 kcal= 10,000 cal
One thermochemical calorie is exactly 4.184 joules, a definition fixed by convention rather than by a water experiment. The food calorie on a nutrition label is a kilocalorie of 4,184 joules.
The small calorie appears in chemistry, physics and heat-capacity problems, where a substance's specific heat is expressed per gram per degree. Nutrition labels use the much larger food calorie instead.
Kilocalories to BTU
One kilocalories is 3.965667 btu, and one btu is 0.252164 kilocalories.
A BTU (British thermal unit) is 1,055.05585262 joules — the energy needed to heat one pound of water by one degree Fahrenheit. It is used for heating and cooling capacity.
- 1 kcal= 3.965667 BTU
- 5 kcal= 19.828334 BTU
- 10 kcal= 39.656668 BTU
What kilocalories are used for
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.
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.
All factors are exact definitions, so only the display is rounded.
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 kilocalories.
One unit of electricity on a Tanzanian prepaid meter
1 kWh = 860.42065 kcal
The average domestic rate was about 229.59 TZS per kWh as of December 2025, including taxes and supply. That is an average across domestic customers, not the marginal rate on a bill.
Source: GlobalPetrolPrices — Tanzania electricity prices (compiled from EWURA/TANESCO tariffs) · verified 2026-09-14
Kilocalories conversion tables
Kilocalories to Joules
| Kilocalories (kcal) | Joules (J) |
|---|---|
| 1 | 4,184 |
| 2 | 8,368 |
| 3 | 12,552 |
| 4 | 16,736 |
| 5 | 20,920 |
| 10 | 41,840 |
| 25 | 104,600 |
| 50 | 209,200 |
| 100 | 418,400 |
Kilocalories to Kilojoules
| Kilocalories (kcal) | Kilojoules (kJ) |
|---|---|
| 1 | 4.184 |
| 2 | 8.368 |
| 3 | 12.552 |
| 4 | 16.736 |
| 5 | 20.92 |
| 10 | 41.84 |
| 25 | 104.6 |
| 50 | 209.2 |
| 100 | 418.4 |
Kilocalories to Megajoules
| Kilocalories (kcal) | Megajoules (MJ) |
|---|---|
| 1 | 0.004184 |
| 2 | 0.008368 |
| 3 | 0.012552 |
| 4 | 0.016736 |
| 5 | 0.02092 |
| 10 | 0.04184 |
| 25 | 0.1046 |
| 50 | 0.2092 |
| 100 | 0.4184 |