The Federal Reserve Boardcalculates this index by compiling indices of physical output from avariety of agencies and trade groups, weighting each index by the Census' value added, and adding it to the cost of materials. When physical measures are not available, the Federal Reserve Board uses the number of production workers or amount of electricity consumed as thebasis for the index. To convert industrial production into dollars, multiply by the "real value added" estimate used by the Federal ReserveBoard.