We analyze the steady-state (Gaussian) beam fanning in LiNbO3 from the nonlinearly coupled Kukhtarev equations by including both diffusive and photovoltaic effects and by adding the thermal effect in the calculation. There is good agreement between theory and experiment. The results show a symmetric beam-fanning pattern whose size depends on the beam waist and the power. Possible applications of our results in nondestructive testing of material parameters and optical limiting are discussed.