Im 5 feet tall and weigh 126 pounds how many calories do you have to eat each day to lose 3 pounds of fat each week?

If you lead a moderately active lifestyle, than eating about 1200-1400 Calories a day will help you lose the weight in about two weeks.

The math:

One pound = 3500 Calories

Eating 1200-1400 Calories a day = around a 700 Calorie deficiency

3500Calories/700Calories = 1 pound every 5 days

About three pounds in two weeks.

But when it all comes down to it, it's not the pounds that should matter. It's the physique that does. Why don't focus more on working out and building muscle and tone instead of counting the pounds? Good luck.