40 Calories to kJ

The working

Shown to 2 decimal places, as the app shows it. One food Calorie (kcal) is 4.184 kilojoules.

kJ, Calories and kcal

Calories are the unit most recipes and fitness apps use. A food Calorie, written Cal here and also called kcal, is 4.184 kJ, and kilojoules (kJ) are what many food labels show. 40 Cal is 167.36 kJ, so a tracker that says 40 Cal and a label that says 167.36 kJ describe the same energy.

This is a small amount of energy, closer to a single piece of fruit or a drink than to a meal.

For scale, half of this amount is 20 Cal, which is 83.68 kJ. Twice it is 80 Cal, which is 334.72 kJ.

Foods with about this much energy

• About the same as a mandarinOne serving is 40 Cal (167.36 kJ).
• About the same as a kiwiOne serving is 42 Cal (175.73 kJ).
• About the same as a rice cakeOne serving is 35 Cal (146.44 kJ).

These are everyday single-serving estimates from the app's food list, not nutrition labels. Recipes and portions vary. See the whole list.

Walking guide

4 to 13 min of walking.

Adult reference guide: 45 to 120 kg at a reference walking pace. Actual times may be outside this range. The exercise page lists the other activities.

Nearby values

• 25 Cal is 104.6 kJ
• 30 Cal is 125.52 kJ
• 50 Cal is 209.2 kJ
• 60 Cal is 251.04 kJ

• Previous: 30 Cal
• Next: 50 Cal
• The other way: 150 kJ to Calories
• All conversions