For those of you cutting, you can use this formula as a "guide." It will help with avoiding atrophy and ensure that you are on the right track.

Lean Body Mass (LBM)
(divided)
1.0 - Desired Bodyfat

Example: 200 lbs @ 10% bodyfat = 20 lbs of fat.
200 - 20 = 180 lbs of LBM
Desired Bodyfat is 4%
1.0 - .04 = .96
180 divided by .96 = 188 lbs
The person should weigh close to 188 lbs @ 4%!!!

This is done on paper, it will vary if hypertrophy/atrophy occurs.
Hope this helps.