Discovery of nanographitic structure of remarkable properties such as fullerenes, carbon nanotubes and three-dimensional graphite nanoplatelets (3D-GNPs) opens the door for potential applications in science and technology. In the present work, graphite intercalation compound (GIC) technique with different acids ratio has been optimized for exfoliated graphite nanoplatelets (EGNPs), and the same optimum acids ratio has been used to successfully produce 3D-GNPs of 10 graphene layers and 145-nm lateral size. Raman spectroscopy, SEM, HRTEM and DLS techniques have been used to evaluate the thickness and number of layers of both EGNPs and 3D-GNPs. A new empirical formula based on Raman analysis has been introduced for the first time to evaluate the number of graphene layers, and it has been verified by using SEM, HRTEM and DLS results. This formula has been tested as well by using experimental data from the literature and found to be consistence and trusty used up to 30 graphene layers. Also, lateral size of graphitic structure has been measured and then evaluated by Lotya formula based on DLS data. The suggested empirical formula along with Lotya formula will open the door in the future work for extensive trials of GIC till reach to monographene layer.