Will It Fit Through the Door Calculator
Will your sofa, couch or furniture fit through the door? Compare its depth, height and diagonal depth with the door opening, and check if it can turn a 90° hallway corner — in cm or inches.
How it works
fits upright if depth ≤ door width and height ≤ door height · on its back/side if height ≤ door width · tipped if diagonal depth ≤ door width · 90° corner (equal hallway width a, piece width w): longest flat length = 2 × (√2 × a − w)
Movers check three things. First, whether the piece’s cross-section (depth × height) passes the clear door opening — measured from the door stop to the face of the open door, which is often 5–8 cm (2–3″) less than the frame. If the depth is too big, the sofa can go through on its back or side when its height is less than the door width. Sofas with a sloped back can also be tipped back: then the “diagonal depth” must be less than the width. Finally, a long piece must turn any 90° corner: in a hallway of width a, the longest rigid piece of width w that turns flat is 2(√2·a − w); longer pieces must be stood on end and pivoted, which needs ceiling height.
Worked example
A sofa 210 cm long, 90 cm deep and 78 cm high and a door 80 cm wide by 200 cm high: upright it is 90 cm deep, wider than the door, but on its back the height of 78 cm passes with 2.0 cm of clearance — it fits on its back or side. In a 100 cm hallway the longest piece that turns flat is 2 × (141.4 − 78) = 127 cm, so the 210 cm sofa must be stood on end to turn.
Sources: IKEA — How to measure for furniture delivery · Moving sofa problem — corner geometry (Wolfram MathWorld)
Frequently asked questions
How do I know if a couch will fit through my door?
Measure the door’s clear width and height, then the couch’s depth, height and diagonal depth. If either the depth or the height is less than the door width, it can pass (upright or on its back); if not, the diagonal depth must be smaller than the width for it to tip through.
How do I measure the diagonal depth of a sofa?
Lay a straight edge from the top of the back to the front of the arm, then measure from the bottom back corner to the edge at a right angle. That smallest distance is the diagonal depth used when the sofa is tipped back through a door.
How can I gain extra space at the door?
Remove the door from its hinges (often gaining 4–5 cm or 2″), take off the door stop, unscrew the sofa’s legs and, on some models, the arms or back. Protect the frame with blankets.
What if it does not turn the hallway corner?
Stand the piece on end and pivot it upright, which works if the ceiling is higher than its length or diagonal. Otherwise look for a sectional, modular or flat-pack model, or another route such as a window or patio door.
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This calculator is for educational purposes. Double-check important results before acting on them.