kcal and food Calories are the same size unit

Read the unit before multiplying

In nutrition, a food Calorie (capital C) is one kilocalorie: 1 kcal = 1 food Calorie = 1,000 small calories. The thermochemical conversion used here is 1 kcal = 4.184 kJ.

For example, 259 kcal on a food label is 259 food Calories, not 259,000 food Calories. It is 259,000 small calories. Labels and everyday writing do not always preserve capital letters, so use the context.