How to measure for a new sofa, and the way in

Most sofas that go back to the shop fit the room perfectly. They did not fit the hall (sample guide).
Measure the front door with the door open, from the frame to the edge of the open door: that is the real width. Then find the tightest turn on the way to the room, and the headroom where the stairs turn.
Compare those numbers with the sofa’s depth and height, not its width: sofas go in on their side or on end. Every label in our showroom gives the narrowest door each piece goes through.