It seems that I have been seeing some people that do this. I know how it works but I wanted to know is how do you come up with the formula for how many calories to use? How many different numbers do you shift to a week and do you just count calories or do you count fat, carb, ect?

At your height and weight, I would shift between 1400 - 1800 OR 1600 - 2000. It depends on your body. Give both sets of numbers a try for 2 to 3 weeks and see how your loses are. The greater the losses, the better the plan. It's about experimenting!

I plan on an average of 1500 a day, so I multiply that by 7, = 105,000, and then choose how to eat that over the week.

I weigh once a week, and tend to eat more that day, high to medium as the week goes on, and quite low on the 2 days before the next weighday - but that's just me.

Good luck!