Man that is a hard one... it depends on a gazillion things:
1. How much BF% you have just now
2. How loong have you had it (is it the years old stubborn one???)
3. How much cardio you do, on what intensity, for how long, how often?
4. Genetics (simply put).
I wouldn't venture into giving you an estimate, because I will most likely be off than on the money...
My results are:
6 feet
215 pounds
cardio 6 times per week: 45 min @ 75 ~ 80% MHR
training 45 ~ 60 min, 4 times per week.
I calculated I have a weekly deficit of 9600 cals (between my diet and the expenditure from training and cardio).
With that many calories in negative, I should be loosing 1.25 kilos pure fat per week (about 2.something pounds), but I am not...I constantly loose about 900 grams fat per week; and I have to be happy with it, since I cannot cut calories any more and I cannot increase either intensity (well, maybe yes) or lenght of the cardio. Besides, last thing I want is my body adapting to the cardio and learning how to do it cheaper...
You will have to track your progress and then approximate. This is what I have been doing...now I can see the trend over 17 weeks.
Cheers