General calculation:
2Row=103*LME/EFF
2Row=129*DME/EFF
6Row=110*LME/EFF
6RoW=136*DME/EFF
Wheat=98*LME/EFF
Wheat=122*DME/EFF
Where LME and DME are amounts of extract in pounds
EFF is the mashing efficiency in %
Example:
6lb of DME in a 70% mash efficiency system:
Required 2 row = 129*6/70 = 11lb