In order to lose weight, first you have to figure out your maintenance caloric intake; the amount of daily calories you need to maintain your body mass. This will depend on your age, gender, height, body weight, and activity level. 

Setup your weekly goals (how much body fat you want to lose), and the duration of your diet in weeks. The calculator will tell you how much daily calories you need to consume and your target weight after the specified diet period.

Once you know your maintenance calories, you need to consume 500 – 1000 calories less than that, which corresponds to 1 to 2 pounds of body fat a week. 

One pound of body fat corresponds to approximately 3500 calories. So, if you create that deficit in 1 week, you will lose 1 pound of body fat. This means that you need to consume 500 calories less than your maintenance calories. If you create a deficit of 7000 calories a week (1000 calories a day less than your maintenance intake), you will lose 2 pounds, and so on.

We do not, however, recommend losing more than 2 pounds of body fat a week because it is not sustainable on the long run and you could risk losing muscle tissues, too.

Here, you can find how much that translates into macronutrients in grams.