The average adult needs to burn about 8,700 kilojoules (kJ) per day to maintain their current weight. This amount varies depending on factors like age, sex, muscle mass, and activity level. For weight loss, a common strategy is to create an energy deficit by burning more kilojoules than consumed, typically aiming to burn or reduce intake by about 2,000 kJ per day to lose roughly half a kilogram of fat per week. Daily physical activity recommendations to help burn kilojoules include at least 30 minutes of moderate exercise most days. Thus, the number of kilojoules you should burn daily depends on individual factors and your specific goals such as maintenance, weight loss, or weight gain, with 8,700 kJ being an average target for maintenance in adults.