Baseboard calculator
Wall by wall, with a cut plan for the lengths your shop sells.
By Rohit GaurLast updated September 18, 2026Report a mistake
Set what your measurements are good to and the quantities below allow for the largest the rooms could be.
US baseboard is usually sold in 16 ft lengths, UK skirting in 4.2 m. Type whatever your merchant stocks.
Off: each wall is cut from its own piece, which is what you need if you would rather not join a short run. On: the total length is simply divided.
What to buy
4 pieces
3 if you join offcuts between walls. The difference is the short ends that cannot make a wall on their own.
- Wall run
- 48 ft
- Trim on the wall
- 48 ft
- Offcut
- 16 ft
The cut plan
- Piece 112 ft4 ft left
- Piece 212 ft4 ft left
- Piece 312 ft4 ft left
- Piece 412 ft4 ft left
The cut plan does not take the doorways off, because a doorway splits a wall in two and the calculator cannot know where on the wall it sits. It is the safe number; the length above is exact.
Rooms
Cutouts (taken off)
Extra areas (added on)
Use the height set above
Share this calculation
The link holds the measurements themselves, so it opens the same calculation on any device.
Why dividing gets this wrong
A room with four 3 m walls needs 12 m of skirting. Divide by the 4.2 m lengths a British merchant sells and you get three, so three is what most calculators say. Buy three and you will be a whole wall short.
The reason is that each stick leaves 1.2 m over, and 1.2 m cannot make a 3 m wall. Trim is cut wall by wall, so the answer depends on how the walls fall — not on the total. This page plans the cuts: longest run first, into the first stick with room for it, and the plan is shown so you can check it against the room.
Turn on join offcuts if you are happy to put two short pieces on one wall with a joint between them. Then dividing is right, and the page divides.
Where the walls come from
They come from the same outline the drawing above uses. A 12 × 14 rectangle is four walls of 12, 14, 12 and 14 — not a perimeter of 52 that has lost the shape it came from. An L-shaped room gives six walls, a triangle entered by its three sides gives three.
A round room has no straight walls to cut trim for, so the page falls back to dividing and says so. A triangle entered as a base and a height has no known sides at all, and is left out of the total.
Doorways
The length figure takes the doorways off, because no trim runs across a doorway. The cut plan does not, and this is deliberate: a doorway splits a wall into two shorter runs, and where on the wall it sits changes the cuts. The calculator has no way of knowing that, so it plans the walls as drawn and gives you the safe number.
Doors are the ones you enter on any estimator page — enter them once and the paint calculator knows about them too.
Stock lengths
US baseboard profiles are sold in 8 ft and 16 ft; British skirting is mostly 4.2 m, with 2.4 m the common short length. These are regional facts rather than unit ones: switching this page to metres does not turn a North American lumber yard into a British one, so the shortcuts follow the region and you can type any length you like.
Where these numbers come from
- Moulding and trims: baseboard profiles in 8 ft and 16 ft — Alexandria Moulding
Lengths are listed per profile rather than in a filter, and the catalogue runs to 67 pages, so this is the first page rather than a full census. The 7 ft and 14 ft lengths on it belong to door stop and casing, not baseboard.
Checked 2026-09-18
- Skirting boards: 40 products at 4.2 m, 18 at 2.4 m, 6 at 3.66 m — Wickes
Counts read off the category's own length filter, out of 66 products.
Checked 2026-09-18