What size dining table for a 3 m × 3 m room?
90 × 90 cm seats 4 · or round, 110 cm across
A 3 × 3 m room takes a dining table up to 90 × 90 cm (35 × 35 in) square, or a round one 110 cm across; each seats 4. That leaves 91 cm (36 in) from the table's edge to every wall. Made to measure, the table could be up to 118 × 110 cm.
A square room this size is a dining room for 4 if people need to get past the chairs. The limit is not the table: it is the space a chair takes when someone pushes back from it, which has to be found on all four sides.
Where nobody walks behind the chairs, for instance with the table set into a corner or against a window seat, you can shrink the gap on that side. The calculator has a setting for each kind of gap; try the tighter ones before you give up on a bigger table.
Worked out for A dining room 3 × 3 m (9 ft 10 in × 9 ft 10 in) with a rectangular table in the middle and 91 cm (36 in) from its edge to each wall, enough for someone to edge past a seated diner. Change the numbers
The working
- Clearance 91 cm on every side (edge past).
- Longest table: 300 − 2 × 91 = 118 cm.
- Widest table: 300 − 2 × 91 = 118 cm.
- Biggest stock size inside both, by seats then area.
The rules, and their sources
Space behind the chairs
The NKBA's guidelines: 813 mm (32 in) from the table edge to the wall when nobody passes behind a seated diner, 914 mm (36 in) for someone to edge past, 1118 mm (44 in) to walk past. 75 cm is the least for a chair to pull out.
An industry guideline Sources: NKBA, Kitchen Planning Guidelines, Guideline 8: traffic clearance at seating (checked 31 October 2026); furniture.co.uk (Amy, 29 May 2026), Round dining table sizes (checked 31 October 2026); IKEA Indonesia, Ideal dining table height (checked 31 October 2026).
UK stock dining table sizes
UK shops sell rectangular tables from 120 × 80 cm (four) to 260 × 100 cm (ten), round tables 90–180 cm across and ovals from 150 × 90 to 220 × 100 cm.
Shop sizes Sources: furniture.co.uk (Amy, 14 Mar 2026), Dining table size guide (checked 31 October 2026); furniture.co.uk (Amy, 29 May 2026), Round dining table sizes (checked 31 October 2026); Castlery UK, Round dining tables (checked 31 October 2026).
Table edge per diner
A rule designers use: give each diner at least 60 cm of table edge (24 in). The NKBA asks for a 610 mm (24 in) wide place at a 30 in table.
A rule designers use Sources: IKEA Switzerland, How much space per person at a dining table (checked 31 October 2026); NKBA, Kitchen Planning Guidelines, Guideline 9 (checked 31 October 2026); furniture.co.uk (Amy, 14 Mar 2026), Dining table size guide (checked 31 October 2026).
Other room sizes
The biggest stock rectangular table that leaves 91 cm (36 in) on every side of each room.
| Room | Biggest table | Seats |
|---|---|---|
| 2.5 × 3 m8 ft 2 in × 9 ft 10 in | no stock size— | — |
| 3 × 3 m9 ft 10 in × 9 ft 10 in this page | 90 × 90 cm35 × 35 in | 4 |
| 3.05 × 3.66 m10 × 12 ft | 180 × 90 cm71 × 35 in | 6 |
| 3 × 4 m9 ft 10 in × 13 ft 1 in | 200 × 100 cm79 × 39 in | 8 |
| 3.66 × 4.27 m12 × 14 ft | 240 × 100 cm94 × 39 in | 8 |
| 4 × 5 m13 ft 1 in × 16 ft 5 in | 260 × 100 cm102 × 39 in | 10 |
Change the numbers
Your sizes will differ. The dining table size calculator opens with these numbers filled in: change any of them and the answer, the working and the drawing follow.
Editorial notes
Worked out by the Snuug team on 12 November 2026 with the same code as the dining table size calculator, so the two cannot disagree. Every rule cites its source, with the date we last checked it. A rule designers use is a convention, not a study.