The presence construction materials in an ore deposit can add value to the deposit and affect cut-off grade. In this paper, the influence of the presence of granite and aplites on the cut-off grade and ore reserve of Itakpe Iron ore deposit has been studied. This study was carried out by converting the values and production costs of the construction stones to their main ore equivalent using some mathematical models. The study shows that by adding the value of the construction materials to the value of the iron ore, cut-off grade of Itakpe iron ore decreases from 30%Fe to 28.16%Fe. This corresponds to an increase of mineable ore reserve from 137.25mt to 151.34mt given the operating economic parameters.