For intervention studies involving binary treatment variables, procedures for power analysis have been worked out and computerized estimation tools are generally available. The purpose of this study is to: (1) develop the statistical formulations for calculating statistical power, minimum detectable effect size (MDES) and its confidence interval, and minimum required sample size to detect the effects of a continuous moderator variable at level 1 or level 2 in two-level simple cluster random assignment designs; and (2) operatize these formulas in the enhanced version of PowerUp! to create spreadsheets for calculating MDES. This report only shows the preliminary results of the MDES for detecting a level-2 continuous moderator effect in two-level cluster randomized experiments. The formulas for statistical power and the minimum required sample sizes will be derived accordingly.