NiftyRecipe Online energy conversion
MJ/kWh 0.277778 kJ/cal 239.005736 kcal/cal 1000 kJ/kcal 0.239006 MJ/cal 239005.736138 kWh/kJ 3600
cal / kJ

40 calories in kilojoule

0.16736 kilojoule

1 cal = 0.004184 kJ · factor

Nutrition packaging often lists both kcal and kJ. This tool applies a fixed conversion ratio only.

Enter a value and click Calculate - opens the page with the new result

Common values

kilojoule to calorie 1 calorie in kilojoule 2 calories in kilojoule 3 calories in kilojoule 4 calories in kilojoule 5 calories in kilojoule 6 calories in kilojoule 8 calories in kilojoule 10 calories in kilojoule 12 calories in kilojoule 15 calories in kilojoule

Same amount, other units

40 calories → kcal 40 calories → BTU 40 calories → kWh 40 calories → MJ

Related converters

cal → kcal cal → BTU cal → kWh cal → MJ
Formula: calorie to kilojoule

kJ = cal × 0.004184 (1 CAL = 0.004184 KJ)

Reference values: calorie → kilojoule
cal kJ
1 cal 0.004184 kJ
100 cal 0.4184 kJ
200 cal 0.8368 kJ
500 cal 2.092 kJ
1000 cal 4.184 kJ
2000 cal 8.368 kJ

All amounts for this pair

FAQ for cal → kJ
40 calories in kilojoule

40 calories is 0.16736 kilojoule using the standard food-energy factor on NiftyRecipe.

Package labels, recipe macros and fitness apps often jump between kilocalories and smaller calorie units (or kilojoules). Here the ratio stays constant: 1 calorie = 0.004184 kilojoule, so 40 calories always maps to 0.16736 kilojoule until you change the input. The reverse figure is 1 kilojoule ≈ 239.005736 calorie.

Use the field above to try another portion size, scale a recipe, or match two apps that print different units. Everything on this page stays inside nutrition-style energy units-no length, temperature or other measures mixed in.