The size that works best for a kitchen island can vary depending on the size of your kitchen and what you need it for. A good starting point is a kitchen island that's 24 inches wide by 36 inches long, which gives you enough space for basic cooking and storage. If you want to add seating, make sure there's at least 12 inches of clearance for comfort. In kitchens, a compact 3-by-4-foot island can provide useful workspace without making the room feel cramped. To maintain the balance and functionality of your kitchen, the total area taken up by the island should not exceed 10% of the square footage.