Energy converter
Joules, calories, watt-hours, electronvolts and BTU, with the applied convention shown.
Result
Converted value
4.184 kJ
- Formula
- 1 kcal = 4.184 kJ
Calculation, assumptions and sources
OverviewAn energy converted between joules, thermochemical calories and kilocalories, watt-hours, electronvolts, BTU and their multiples.
An energy converted between joules, thermochemical calories and kilocalories, watt-hours, electronvolts, BTU and their multiples. Calorie and BTU have several definitions: the one used is displayed with the result.
Method & formulasE = P × t
E = P × t1 Wh = 3600 J (exactly)1 eV = 1.602176634 × 10⁻¹⁹ J (exactly)
An energy is a power integrated over a duration. Since the 2019 SI redefinition, which fixed the elementary charge, the electronvolt equals an exact number of joules.
- J
- Joule (J)
- kJ
- Kilojoule (kJ)
- MJ
- Megajoule (MJ)
- cal
- Thermochemical calorie (cal)
- kcal
- Thermochemical kilocalorie (kcal)
- Wh
- Watt-hour (Wh)
- kWh
- Kilowatt-hour (kWh)
- eV
- Electronvolt (eV)
- keV
- Kiloelectronvolt (keV)
- MeV
- Megaelectronvolt (MeV)
- BTU
- BTU (international table)
- cal
- Thermochemical calorie (exactly 4.184 J). The international-table calorie (4.1868 J) and the 15 °C calorie (≈ 4.1855 J) are other definitions in use.
- kcal
- Thermochemical kilocalorie (exactly 4184 J), the “Calorie” of nutrition labelling.
- BTU
- International-table BTU (1055.05585262 J). At least five BTU definitions coexist (thermochemical, 39 °F, 59 °F, 60 °F), differing by a few tenths of a percent.
The three calories in use differ by at most 0.07%: negligible for nutrition, significant for a precise thermal balance.