Estimation of creep of concrete and the resulting long-term deflections and prestress losses are important factors in the design of Reinforced and Prestressed concrete structural elements. Rational modeling of creep is required to ensure the safety and serviceability of structural elements during their service life, while a number of models have been proposed for estimation of creep of concrete for design purposes, a satisfactory model is yet to evolve due to the complexity exhibited by concrete creep. Recent investigation has shown that the knowledge about the nanoscale properties of C-S-H phases can be used along with multiscale modeling of concrete to determine creep properties of concrete. This paper presents the investigations carried out on determination of creep of concrete based on creep properties of nanogranular C-S-H phases. The upscaling of the viscoelastic properties of concrete have been done by using the formulation given by Pichler and Lackner[1]. This model links creep compliance of concrete at a macroscale, to the composition of concrete at microscale, which has been validated by comparing with experimental results available in open literature