Objective was to determine the true fecal digestibility of calcium and phosphorus in the growing pig fed corn and soybean meal (SBM) based diets. Emphasis was put on the calcium to phosphorus  ratio and how it relates to growth performance of the growing pig. Results showed no average daily gain differences between diets containing different calcium to phosphorus ratios. In conclusion, true fecal digestible calcium to phosphorous ratios of 0:9:1 to 1:0:1 showed optimal gain to feed ratios as well as fecal digestibility of phosphorus and utilization of phosphorus by growing pigs fed corn SBM based diet.