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Energy converter
Energy and work, including the two different calories. 9 units, converted from one table of exact factors.
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Worth knowing. The "calorie" on food packaging is a kilocalorie — a thousand of the calories physicists use. Both are in the table, which is where most confusion here comes from.
1 kilocalorie in every other energy unit
Computed by the same engine that runs the converter above, so these can never drift apart from it.
| From | Equals | Unit |
|---|---|---|
| 1 kilocalorie | 4,184 | joule (J) |
| 1 kilocalorie | 4.184 | kilojoule (kJ) |
| 1 kilocalorie | 1,000 | calorie (cal) |
| 1 kilocalorie | 1.1622222 | watt hour (Wh) |
| 1 kilocalorie | 0.0011622222 | kilowatt hour (kWh) |
| 1 kilocalorie | 3.9656668 | BTU (BTU) |
| 1 kilocalorie | 3,085.96 | foot-pound (ft·lb) |
| 1 kilocalorie | 2.6114474 × 10^+22 | electronvolt (eV) |
What each unit actually is
Most converters give you a number and stop. Where a figure is exact by definition we say so, and where it is an average or shifts with conditions we say that too — that is usually the thing you needed to know.
| Unit | Symbol | What it actually is |
|---|---|---|
| joule | J | The SI derived unit. |
| kilojoule | kJ | Exact. The energy unit on food labels outside the US. |
| calorie | cal | The small or gram calorie. Exactly 4.184 J. |
| kilocalorie | kcal | 1,000 small calories. THIS is the "calorie" on food labels and in diets — the everyday food calorie is a kilocalorie. |
| watt hour | Wh | Exact. |
| kilowatt hour | kWh | Exact. The unit electricity is billed in. |
| BTU | BTU | The international-table British thermal unit. Several slightly different BTUs exist; this is the standard one. |
| foot-pound | ft·lb | Exact. |
| electronvolt | eV | Exact since the 2019 SI redefinition. |