Understanding the conversion between kilojoules (kJ) and calories (Cal) is essential for accurate dietary energy assessment. One kilojoule is approximately equal to 0.239 food calories, while one food calorie equals about 4.184 kilojoules. To convert kilojoules to calories, multiply the energy in kilojoules by 0.239; conversely, to convert calories to kilojoules, multiply the energy in calories by 4.184. For example, 500 kJ is approximately 119.5 calories (500 kJ × 0.239), and 500 calories is about 2,092 kJ (500 Cal × 4.184). This conversion is particularly useful for interpreting nutritional information and managing energy intake.