PEMSoft MD+Calc is an innovative, interactive web-based calculator tool for rapid customized diagnostic and therapeutic assessments. MD+Calc provides pediatric-specific equations and scores for clinical practice, including A-a gradient, anion gap, CSF WBC correction for RBCs, endotracheal tube sizes (cuffed and uncuffed), sodium correction in hyperglycemia, Apgar score, and the Ottawa ankle rules. Dr. Graham Walker, a PEMSoft Editor, developed the original version of “MD+Calc”.