Medical Questions › Category: Drug information › what meaning .4 in calculation k deficit 0 Vote Up Vote Down aly asked 6 years ago 1 Answers 0 Vote Up Vote Down Dr. Adil Ramzan Staff answered 6 years ago HI, 0.4 is constant, this value doesn’t change, 0.4 is used when the expected potassium used is 3.5. If you use 4.0 as expected potassium then use 0.6 as the constant value. Thank you.