Energy Converter
Convert food Calories (kcal), kilojoules and joules using the thermochemical definition of a calorie.
Your inputs
418.4 Kilojoules (kJ)
100 Kilocalories (food Calories)
One kcal equals exactly 4.184 kJ here. Food label rounding may differ.
Let’s work it out.
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How to use Energy Converter
- Enter the amount you want to convert. Zero is allowed; negative amounts are rejected.
- Choose the source unit and the target unit. Results update after a short pause.
- Read the converted amount and equivalent-unit cards. Use Copy result or Print if needed.
Worked example
100 kcal × 4.184 = 418.4 kJ.
Formula, accuracy & limitations
Target amount = entered amount × source-unit factor ÷ target-unit factor. Base-unit factors: kcal = 4184; kj = 1000; j = 1.
One kcal equals exactly 4.184 kJ here. Food label rounding may differ.
Calculations use your inputs. Main numeric values show up to six decimal places, percentages up to two, and chart labels up to four. Time results use hours, minutes and seconds. Very small nonzero values use scientific notation.
Read the measurement reference ↗Check the energy definition on the label
The selected kcal is the thermochemical kilocalorie: 4184 joules. A food Calorie is one kcal. This conversion does not estimate calories burned, digestibility or the energy content of a food without a supplied energy value.
Read the energy converter result
Convert food Calories (kcal), kilojoules and joules using the thermochemical definition of a calorie. One kcal equals exactly 4.184 kJ here. Food label rounding may differ. Change one input at a time to see which measurement drives the result. Copy the calculated values only after checking the selected units against your original measurement.
Frequently asked questions
Is a food Calorie one calorie or one thousand?
A food Calorie, commonly written kcal, is 1000 small calories. Select kcal for food-label energy; this page uses the thermochemical calorie definition.
Why can two food labels look slightly different after conversion?
Labels may round energy before printing. Converting that rounded number can differ from a value computed using the original nutrient data.
How is energy conversion worked out?
Target amount = entered amount × source-unit factor ÷ target-unit factor. Base-unit factors: kcal = 4184; kj = 1000; j = 1.
What would the sample inputs produce?
100 kcal × 4.184 = 418.4 kJ.
