Board Thread:Support Requests - Designing Your Wiki/@comment-35616940-20190121224953/@comment-9605025-20190121232053

Have you read Help:Achievements? I am not aware of any specific dimensions that are required. However, according to the Badge Wiki, the default images are available in the following sizes: 40x40, 56x56, 82x82, 90x90, 128x128.