Successful use of sensor based nitrogen (N) rate recommendations has resulted in an increase in N use efficiency (NUE) in winter wheat production. Due to increasing N fertilizer costs, development of a functional algorithm to optimize N fertilization in corn production is also essential. This study was conducted to formulate the in-season N optimization fertilizer algorithm (NFOA) that will be used to estimate the mid-season N rate requirement to maximize corn growth and minimize inputs.  In addition, the optimum resolution to treat spatial variability for NFOA-based sidedress N rates was determined. The experiment was established at three locations in 2004 (Efaw, Perkins and LCB) near Stillwater, OK consisting of 13 treatments arranged in a randomized block design (RCBD) with 3 replications.  Treatments consisted of three application methods: split application with preplant rates at 0 and 67 kg ha^-1 and sidedress rates at 67 kg ha^-1 or NFOA-based variable rates, preplant and sidedress only at 0, 67 and 134 kg ha^-1.  In addition, one NFOA-based N rate was tested at 0.34 and 2.32 m² application resolutions. Generally, higher grain yield (17% at Efaw in 2005) was obtained in plots with pre-plant N and mid-season NFOA-based N rates. High NUE values were obtained from plots without pre-plant N but applied with NFOA derived mid-season N rates.  While the NFOA employed increased grain yield for selected sites, NUE was consistently improved across site-years. Improved NUE was attributed to lower N inputs determined by the algorithm which is based on estimated yield potential.