How much skirting board for a 3 m × 4 m room?
13.24 m (43 ft 5 in) 8 × 2.4 m boards, or 4 × 4.2 m
A 3 × 4 m room with 1 door needs 13.24 m (43 ft 5 in) of skirting board: buy 8 × 2.4 m boards, or 4 × 4.2 m boards. The room's perimeter is 14 m (45 ft 11 in); the doorway is the only part with no skirting.
Count boards, not metres. A board that is a little short of its wall cannot be stretched, so each wall is rounded up to whole boards and the offcuts are waste. Longer boards mean fewer joins on the long walls, which is worth the extra cost where the wall is on show.
Add a board if the room has a chimney breast or alcoves: every return needs its own short length, and the mitred corners eat a little of each board.
Worked out for A plain rectangular room 3 × 4 m (9 ft 10 in × 13 ft 1 in) with 1 door, and skirting on every wall. Change the numbers
The working
- Perimeter: 4 walls, 14 m. Skirting: 14 m − 1 × 0.76 m door = 13.24 m
- Each wall takes whole boards, joined only where the wall is longer than a board. By board length, that is 8 × 2.4 m, or 6 × 3.05 m, or 4 × 4.2 m.
The rules, and their sources
UK skirting board lengths
UK MDF skirting is sold in 2.4 m lengths at DIY stores and 3.05 m or 4.2 m lengths from skirting makers.
Shop sizes Sources: B&Q, Metsä Wood primed MDF square skirting board, 2.4 m, pack of 4 (checked 31 October 2026); MDF Skirting World, The length option (checked 31 October 2026).
Standard UK internal door
The most common internal door in England and Wales is 762 × 1981 mm (2 ft 6 in × 6 ft 6 in). The gap you can carry a sofa through is smaller.
Shop sizes Source: Howarth Timber (Green, 14 Sep 2026), UK door sizes (checked 31 October 2026).
Other room sizes
The run of skirting for each room with 1 door, and the count of the shortest and the longest stock boards.
| Room | Skirting to fit | Boards |
|---|---|---|
| 3 × 3 m | 11.24 m (36 ft 10 in) | 8 × 2.4 mor 4 × 4.2 m |
| 3 × 4 m this page | 13.24 m (43 ft 5 in) | 8 × 2.4 mor 4 × 4.2 m |
| 4 × 4 m | 15.24 m (50 ft) | 8 × 2.4 mor 4 × 4.2 m |
| 4 × 5 m | 17.24 m (56 ft 7 in) | 10 × 2.4 mor 6 × 4.2 m |
| 5 × 6 m | 21.24 m (69 ft 8 in) | 12 × 2.4 mor 8 × 4.2 m |
Change the numbers
Your sizes will differ. The room 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 room 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.
Other sources the calculator draws on:
- DCLG, Technical housing standards: nationally described space standard (March 2015, notes added 19 May 2016), Table 1 and paragraph 10, checked 31 October 2026
- The Licensing of Houses in Multiple Occupation (Mandatory Conditions of Licences) (England) Regulations 2018 (SI 2018/616), regulation 2, checked 31 October 2026
- Which? (Garber, 14 Apr 2018), Shrinking homes: the average British house is 20% smaller than in the 1970s (LABC Warranty analysis of 10,000 Zoopla and Rightmove listings), checked 31 October 2026
- Statista, Average living room sizes in new British houses 1930–2020 (LABC Warranty data), checked 31 October 2026
- MHCLG, English Housing Survey 2018-19, Size of English homes fact sheet, checked 31 October 2026
- Flooring Hut, What widths do carpets come in?, checked 31 October 2026