RUBBER COMPOSITION FOR TIRE

Provided is a rubber composition for tires by which low rolling resistance and wet grip performance are enhanced beyond conventional levels. The rubber composition for tires comprises a diene rubber, silica, and a silane coupling agent, and is characterized in that a function v of a shear modulus G' of the rubber composition at 0.28% shear stress at 110°C, a CTAB specific surface area (CTAB) of the silica, a volume fraction (Õ) of the silica in the rubber composition, and a stress at 100% elongation (M 100 ) of the rubber composition satisfies the relationship of the following equation (i): G' = K × v. In equation (i), K is a coefficient greater than 0 and not greater than 450, and v is represented by the following equation (ii): v = Õ × (1 + 0.0258 × CTAB × M 100 ) and is a real number not less than 2.5 and not greater than 20.