Combine Means & Standard Deviations

Enter one row per group with its sample size n, mean, and SD. This tool computes the combinedmean and SD using two equivalent approaches:

  • algorithm 1: decompose to Σx and Σx2 and then recompute
  • algorithm 2: Cochrane’s sequential combine formula
# n mean SD actions

How to use this page

  1. enter n, mean, and SD for each group (add or remove rows as needed).
  2. click calculate to view combined results (both algorithms).
  3. use load example to replicate the textbook example.