Skirting Board Length Calculator

How it is calculated

The tool treats the room as a rectangle: perimeter = 2 × (length + width). It subtracts the doorways, net = perimeter − doors × door width, then adds a fixed 10 % for cuts and mitres, total = net × 1.10, and finally packs = ceil(total ÷ board length). All lengths are in metres. A blank doors field means no doorways, a blank door width uses 0.9 m and a blank pack length uses 2.4 m, so those defaults apply silently. A value you actually type must make sense: doors must be a whole number of 0 or more, and door width and pack length must be above zero, otherwise there is no result (a door width of 0 is rejected, not replaced by 0.9). The 10 % allowance is built in and cannot be changed, and there is no result if the doorways take up the whole perimeter. For a bundle, enter the total metres in it as the pack length.

Common mistakes

• Adding your own waste allowance on top: the tool already adds 10 %, so a second 10 % buys too much skirting.
• Leaving the door width blank when your doors are not 0.9 m wide; the tool then silently uses 0.9 m, which changes the deduction.
• Entering a fraction of a doorway, such as 1.5 doors, or a negative count. Doors must be whole numbers; for a wide opening enter one door with a larger door width instead.
• Not counting open archways or wide openings as doorways; every gap with no wall must be deducted.
• Forgetting that the result is for a plain rectangle: an L-shaped room, chimney breast or alcove changes the real perimeter, so measure the walls yourself. Lengths are in metres, not centimetres or feet.