Estimating the confidence interval for an exponential failure rate. This calculator assumes continuous time. Specify your sample size N (integer), confidence level, and T = average time until failure T. The failure rate f is 1/T. The Censoring Factor specifies the censoring rate relative to the failure rate. If you can follow all of your subjects until they fail, set it to 0. If 20% of your subjects will be lost to follow-up, set it to 0.2. This means if you start with 5 subjects, you will see 4 failures.