What Is The Smallest Kitchen Island . Because an island can be as small as 40 inches to 40 inches which can still provide enough space for preparing the food in the prep space area or breakfast bar. These design highlights don’t work for every kitchen — however, some kitchens are simply too small for an island. 22 Small Kitchen Island Ideas for Saving Space from www.cannibalnyc.com More than 48 inches is generally overkill. Great photos and video here. Kitchen islands are often places of gathering and a spot to display food and meals.