This paper focuses on the problem of advancing a theorem to estimate the stability bound of delay decay rate α and upper bound delay time τ to guarantee the stability of time-delay systems. Based on the Lyapunov–Krasovskii functional techniques and linear matrix inequality tools, exponential stability and decaying rate for linear time-delay systems are also derived. These results are shown to be less conservative than those reported in the literature. Examples are included to illustrate our results.