Cohen D Effect Size Calculator

Understand the cohen d effect size calculator result

The practical job of Cohen D Effect Size Calculator is comparing effects measured on different scales or checking a research summary. It asks for group 1 mean, group 2 mean, group 1 sd, group 2 sd, group 1 size, group 2 size and reports cohen d and pooled sd. The mean difference is divided by the sample-size-weighted pooled standard deviation. The sign shows direction from group two to group one, while magnitude expresses standard-deviation units. By exposing cohen d and pooled sd, Cohen D Effect Size Calculator makes this specific arithmetic inspectable instead of presenting an unexplained number.

With the page defaults of Group 1 mean 10, Group 2 mean 8, Group 1 SD 2, Group 2 SD 2, Group 1 size 20, Group 2 size 20, the verified output is Cohen d 1, Pooled SD 2. Do not average the two standard deviations when sample sizes or deviations differ. In Cohen D Effect Size Calculator, each labeled default remains visible while you edit, so you can change one assumption at a time and trace how cohen d responds.

Method, limits, and private processing

Interpretation depends on field context, design quality, and uncertainty around the estimate. Cohen D Effect Size Calculator evaluates the entered values entirely in your browser, without sending the inputs to a server. When using its cohen d and pooled sd, retain the stated method and input units because this result is bounded by the assumptions of the mean difference is divided by the sample-size-weighted pooled standard deviation.