You can quickly calculate this yourself:
If your calorie-turnover is 2,500 per day and one lb of body fat contains around 3,500 kcal, you will lose around 2lb of fat in three days. Please note that this is only theoretically and depends on your size, age, weight, activity level and so on.. also you most likely drop more than 2lb in the first days but most of that is water weight which will come back with refeeding
Cheers !