In this paper, we present a comprehensive methodology to dimension an OFDMA (Orthogonal Frequency Division Multiple Access) network. We divide the dimensioning task into sub-blocks and present implementation details of each block. The first block has the objective of determining the spatial SINR (Signal to Interference plus Noise Ratio) distribution over a cell area and the MCS (Modulation and Coding Scheme) probabilities. This task usually relies on extensive Monte Carlo simulations. In this paper, we propose a semi-analytical approach in order to reduce computational time. The second block evaluates dimensioning parameters based on a markovian approach. Our model takes into account mixed traffic profiles, different scheduling policies and MCS probabilities obtained from the first step. Theses two stages (radio coverage and traffic analysis) form together a complete dimensioning process for OFDMA networks.