It is very individual and it depends on your genetics, age, lifestyle etc. For example, someone with a labourer style job will require a lot more daily calories then someone with a desk job. Because the daily calorie requirements are so individual, that's why so many people hire a coach/nutritionist to help them when they are trying to loose weight/body fat.
A good general rule is to multiply your body weight in pounds by 15. This will give you roughly the amount of calories you need to maintain at your current body weight. To loose weight, multiply your body weight in pounds by 12-13. To gain weight, multiply your body weight in pounds by 17-18.
At 100 kilos (roughly 220 pounds), to loose weight you would want to eat -> 220 x 12 = 2640 calories
That would be a good starting point. Base your diet around high protein low fat foods and vegetables. Train with weights 4-5 days per week and do cardio 4-5 days per week.