Energy & Work Converter

Energy & Work Converter

Local Processing

Convert between energy and heat units including joule, kilojoule, calorie, kilocalorie, watt-hour, kilowatt-hour, BTU, and electronvolt.

How It Works & Processing Standards

Convert between the units listed below using J as the base unit.

kJ1 kJ = 1000 J
MJ1 MJ = 1000000 J
cal-th1 cal-th = 4.184 J
kcal-th1 kcal-th = 4184 J
Wh1 Wh = 3600 J
kWh1 kWh = 3600000 J
BTU-IT1 BTU-IT = 1055.055853 J
eV1 eV = 1.602177e-19 J

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Converts food calories (kcal), electricity use (kWh), heating and cooling capacity (BTU) and physics units (J, eV).

Calories are thermochemical calories (1 cal = 4.184 J).

How to Use Energy & Work Converter

  1. 1
    Enter a valueDecimals and negative numbers (for temperature, say) are accepted.
  2. 2
    Choose unitsPick the unit you have and the unit you want. The swap button reverses the direction.
  3. 3
    Read, copy or shareResults show up to six decimal places. Copy them or create a share link with the same value.

Examples

250 kcal in kJ
Input: 250 kcal → kJ
Result: 1046
One kWh in MJ
Input: 1 kWh → MJ
Result: 3.6

Common Use Cases

  • Comparing kcal and kJ on nutrition labels
  • Comparing electricity (kWh) with other energy units
  • Understanding BTU ratings on air conditioners and boilers

Frequently Asked Questions (FAQ)

Are food "calories" cal or kcal?

Nutrition labels usually mean kcal. A 300 kcal bowl of rice is about 1,255 kJ.

How are kW and kWh different?

kW is power (rate); kWh is energy (amount used). Convert power in the Power Converter.

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