Traffic capacity planning is a challenging task in multiple input multiple output (MIMO) & orthogonal frequency division (OFDM) based long term evolution (LTE) cellular networks, resulted from emerging diverse multimedia traffic requirement, together with highly open & flexible air interface design in LTE. In this paper, a new methodology for dynamic real-time capacity planning is proposed for LTE radio network dimensioning, based on unified traffic process mechanism, fresh simulation methodology for air interface, and smart self-evaluation and optimization. By corresponding software design and implementation, it provides powerful tool for LTE network planners to get efficient, accurate and professional capacity planning outcome without much manual effort.