Disclosed is a method for manufacturing an R-T-B based sintered magnet, which includes the steps of: preparing an R-T-B based sintered magnet material; and performing a heat treatment by heating the R-T-B based sintered magnet material at a temperature of 450° C. or higher and 470° C. or lower for 4 hours or more and 12 hours or less, wherein the R-T-B based sintered magnet material is represented by the formula of: uRwBxGayCuzAlqM (100−u−w−x−y−z−q) T, the content of RH is 5% or less by mass in the R-T-B based sintered magnet, 29.5≤u≤32.0, 0.86≤w≤0.93, 0.2≤x≤1.0, 0.3≤y≤1.0, 0.05≤z≤0.5, 0≤q≤0.1, and a relationship of p