1kg of fat contains 7,700 calories. That means you need to burn 7,700 calories to lose 1kg of fat, aka, create a 7,700 calorie deficit over the period of time you want to lose that kilogram (be it a week, month, or longer). In theory, you could do that in a day, if you did loads of walking and ate nothing, but that would NOT be a fun day. The daily calorie intake calculator estimates your daily calories requirements in order to maintain, lose or gain weigh based on your BMR and exercise level. Home; About; ... To lose 0.5 kg per week you need: 1,707 Kcal/day: To lose 1 kg per week you need: 1,207 Kcal/day: To gain 0.5 kg per week you need: 2,707 Kcal/day:. Feb 27, 2021 · During this period of rapid growth and development, boys require an calorie weight loss calculator for teens of 2, calories a day, while girls require an average of 2, calories a day. You must be logged in to post a comment. This would imply creating a calorie deficit of Calories to Calories a week, or to Calories a day. Calorie Deficit Calculator..