This is definitely based on the individual. What you need to do is figure out how many calories per day that you are taking in currently. I recommend writing down everything you eat per day for an entire week. Make sure you add up all of the calories daily and weekly as well. There is an equation or series of equations to figure this out accurately. You will need to figure out your resting metabolic rate. This is very important. What this means is the number of calories you burn at rest. RMR = (height in centimeters x 6.25) + (weight in kilograms x 9.99) – (age x 4.92) – 161. Then you need to figure out your intentional calories rate due to exercise-going to the gym, running, playing sports etc..You will multiply these numbers with your RMR. Sedentary (multiply by 1.2), Lightly Active (multiply by 1.375), Moderately Active (multiply by 1.55), Very Active (multiply by 1.725), Extremely Active (multiply by 1.9) And with this number plus your daily calorie intake, you will figure out how many calories you should eat. To keep this easy without calculations you will keep in mind that 3500 calories is one pound. So in order to lose one pound a week you will need to burn an extra 250 calories per day plus decreasing your daily calorie intake by 250 calories. I know most of this sounds pretty complex so I would recommend getting a personal trainer or nutritionist to figure out these values for you. There are also online calculators out there if you want to skip all of this. Search them on Google, they are out there. Bear in mind that some of these calculators are not that accurate though. If you get your hands on Mifflin-St Jeor Equation Calculator then this would be the most accurate.