The Builder’s ToolkitFree UK building calculators
Free UK trim quantity tool

Skirting Board Calculator UK

Turn the actual wall run that needs skirting into linear metres and whole stock boards. Use the supplier length you can really buy, deduct only genuine openings, and add extra only when you choose to.

Measured wall runActual stock length0% default extra
Illustration representing skirting board and room trim quantity planning

Calculate skirting length and stock boards

Start with a measured total wall run, or use the rectangular-room shortcut. Then subtract only openings where no skirting will be fitted.

m
Total wall length before subtracting openings. Measure individual wall sections and add them where the room is irregular.
m
Enter the actual combined width of doorways, openings or gaps where no skirting will run. Do not use a standard doorway width.
m
Use the length your chosen skirting is really sold in. UK products are available in materially different lengths.
%
Optional. Starts at 0%. Choose an allowance only for your actual cuts, defects, joint strategy or spare requirement.
Linear quantity, not a cutting plan. Dividing total metres by board length shows a planning purchase quantity. Corners, scribes, mitres, wall-by-wall cuts and where you accept visible joints can make a real cutting list need more stock.
Enter the measured run and your supplier’s stock-board length.The result will separate net linear metres, optional extra and whole boards to buy.

How the skirting calculation works

Net run = wall run − actual openings

For rectangular-room mode, wall run is calculated as 2 × (length + width). Openings are deducted only where no skirting will be installed.

Boards = round up(adjusted run ÷ stock length)

The base whole-board count is shown at 0% extra. If you choose an allowance, the adjusted linear run is calculated separately before whole-board rounding.

Why 4.2 m boards and 10% extra are not universal

Current UK stock demonstrates the variation. Wickes currently lists MDF skirting at 2.4 m, Howdens has a broad range of 4.2 m MDF skirting, and Skirting World currently offers 3.05 m and 4.2 m lengths. Skirting 4 U also explains that there is no simple universal wastage percentage because the quantity depends on how important the frequency and visibility of joins is to the job. Those figures are examples, not calculator defaults.

Current UK references checked for this calculator:

Wickes — current 2400 mm MDF skirting example

Howdens — current 4.2 m MDF skirting range

Skirting World — 3050 mm and 4200 mm stock lengths

Skirting 4 U — why a single wastage rule does not fit every skirting order

Worked example

A measured wall run of 18.00 m with 0.90 m of actual openings leaves 17.10 m of net skirting.

Using 4.20 m stock boards and 0% extra: 17.10 ÷ 4.20 = 4.071 theoretical boards, so the planning purchase quantity is 5 whole boards. That is 21.00 m of nominal stock length. It is still not a cut-optimised room plan.

Measure the run before choosing the spare

1. Measure actual walls

For irregular rooms, alcoves or chimney breasts, add the real wall sections rather than forcing the room into a rectangle.

2. Deduct real openings

Measure each doorway or opening where the skirting genuinely stops. There is no need for a standard door-width assumption.

3. Check the boards you can buy

Use the exact supplier length, then decide whether cut layout, finish matching or spare stock justifies an explicit extra allowance.

What this calculator deliberately does not choose

It does not select profile, height, thickness, MDF/timber type, fixing method, corner treatment, joint locations or a universal wastage percentage. It also cannot optimise offcuts across individual wall segments.

Useful next steps

For a whole decorating job, take this result into the Room Decorating Quantity Estimator. If you already know a total timber run for a different purpose, use the Timber Length Calculator. For cutting and spare decisions, see the Waste Allowance Guide.

Planning estimate only. Check the measured wall sections, chosen supplier lengths and your real cutting/joint plan before ordering.

Frequently asked questions

Should I deduct every doorway?

Deduct only the measured width of openings where no skirting will be fitted. Do not apply a generic doorway width to every opening.

Why might I need more boards than the simple division suggests?

Individual wall lengths, corner cuts, damaged ends, grain/profile matching and the decision to avoid visible joins can make a real cutting plan use more material than a total-linear-metre calculation.

Can I use this for architrave?

Not directly. Architrave is normally measured around individual openings, so its cut pattern and stock use are different from a room skirting perimeter.