Generally, you want to allow 24" per person for the width of an island. This island is 9'-6" feet wide. Since one person was going to be seated against a wall, I wanted to give them a little more room. The stock cabinet bases are 24" in depth. I added a support wall that also allowed us to add electric to the island. That is approximately 4.5". The raised counter-top is 12" deep. You need to make sure that you add adequate support for the counter material. There are a ton of options for bracing and support. Your contractor or counter material supplier should be able to offer you suggestions for your project.