Tools
Kitchen Island Size Calculator: Will One Fit Your Room?
By the Hill & May team
Updated 2026
An island is never limited by the size of your kitchen. It is limited by the two gaps either side of it, and those gaps are measured from the front of your units, not from the wall. Lose 650mm to a run of base units, another 700mm to a range cooker, then leave a walkway either side, and a room that looks generous swallows nearly three metres before the island starts. This tool does that subtraction for you: tell it the room and what stands against each wall, and it returns the largest island that actually fits, the clearance you would be left with on every side, and how many stools that island will seat.
1. The room
Measure wall to wall on the bare walls, at floor level. Ignore what is standing in the way for now, the next section deals with that.
2. What stands against each wall
Left and right face each other across the room width. Near and far face each other along the length.
3. Walkways and seating
Doors, drawers and appliance fronts are checked separately and will push a gap wider where they need to.
4. An island you already have in mind (optional)
Worktop size including any overhang, in the units you picked above. Leave blank to skip.
Two numbers do most of the damage. The first is the depth of your units: a base run with a worktop and a door handle eats about 650mm before anyone stands in front of it, and a freestanding range cooker or a tall larder takes about 700mm. The second is the door swing. A range cooker door drops forward roughly half a metre, and someone has to stand behind it holding a hot tray, which is why this tool refuses to leave less than 1100mm between an island and any wall carrying a range, an oven, a dishwasher, a tall larder or a fridge freezer, whatever walkway you asked for.
If the answer comes back short, the fix is usually not a smaller island. It is moving one thing: turning a tall larder into base units, or taking the range off the wall the island wants to sit beside. Try the walls again with one item changed and watch how much the island grows.
