Measuring a room for an extending table
The calculator is only as good as the two room numbers. Five minutes with a tape and these steps gives numbers worth trusting.
1. Measure at chair height, not at the ceiling
Run the tape about 20 in off the floor, where chair backs actually land. Baseboards, heaters and window sills sit at that height and steal an inch or three that a ceiling-level measurement misses.
2. Stop at the nearest thing that will not move
A kitchen counter, a built-in bench, a radiator, a column. For a sofa or a sideboard that stays put, measure to its face. The calculator treats your numbers as walls.
3. Check door swings
Open every door that swings into the area and measure how far it reaches. Subtract that from the side it touches, or plan the table so the chairs sit away from it.
4. Measure twice in each direction
Older rooms are rarely square. Measure length at both ends and width at both ends and use the smaller of each pair.
5. Mark the open size on the floor
Painter's tape on the floor at the fully open size, then a chair pulled out at each place, shows problems no number does: a radiator under one chair, a door that hits a seat back. The compare page lists every step size to tape out.
6. Measure the way in
Long one-piece tops have to turn through hallways and stair landings. The delivery box size is on most maker pages; compare it with the tightest turn on the way in.