I am trying to create a simple month of supply formula. I have seen simple
ones but I think there may be a macro behind it since I cannot get the
formula to transfer.

The formula I saw was:
=monthsofsupply(C5,G5,H5,I5,J5,K5,L5,M5,N5,O5,P5,Q 5,R5)
c5 being beginning inventory and the others being the sales forecast by month.

Any help would be appreciated.