This paper presents a simple procedure for planning a failure-censored life test under the assumption that the lifetimes of test units follow an exponential distribution. The failure number (r) is determined such that the probability of the ratio of the estimated and the true mean lifetime being included in a given interval is greater than or equal to a specified value. Given r, the sample size (n) is determined to terminate the life test within a specified time duration with high probability. Those r and n values are tabulated for some selected values of the parameters involved in the life test.