The Palos R/C Flying Club    The M.A.C. Calculator      The form shown below will calculate the percentage of the Mean Aerodynamic Cord (%MAC) of a model airplane wing for a given position of the CG. If you would like to know the position of the Center of Gravity(CG) as measured from the leading edge of the Root Cord, you should use the form on The Center of Gravity Page.          Enter Root Cord (A):  Enter Tip Cord (B):  Enter Sweep Distance (S): Enter Half Span (Y): Enter Center of Gravity (CG): Sweep Distance @ MAC (C) = Mean Aerodynamic Cord (MAC) = MAC Distance from Root (d) = % Mean Aerodynamic Cord (%MAC) = The Equations C = (S(A+2B)) / (3(A+B)) MAC = A-(2(A-B)(0.5A+B) / (3(A+B))) d = (2Y(0.5A+B)) / (3(A+B)) %MAC B.P.  = ((CG-C) / MAC)*100      [ Home | Club Information | Contests & Events | Flying Field ] [ Photo Gallery | Flight Training | Instructors Corner ] [ Newsletter | Links ] If you have any questions about this site, please contact Al   Copyright © 1998/2001 The Palos R/C Flying Club.  All Rights Reserved.