Can you please answer this! No one answers my questions! 500 kcal a day?

So ive been sticking to eating 1000 kcal a day and its not working as much as i want it to and its really aggrivating me. So how much will i lose in say 1 month if i eat 500 kcal only each day. Could i drop a dress size? I know all the health risks etc, so its pointless reciting them. Thanks xx