Stud Wall Calculator

The standard timber for UK stud walls is CLS (Canadian Lumber Standard) at 38×89mm (marketed as 4×2). This is the most common size available from UK timber merchants like Travis Perkins, Jewson and Wickes. The smaller 38×63mm (3×2) CLS is used for lighter partitions. For taller walls over 2700mm or walls supporting loads, deeper studs such as 38×140mm may be needed.

Use 400mm centres for standard plasterboard fixing — this provides the best support for 12.5mm plasterboard and is the standard spacing used by most carpenters. Use 600mm centres when the void will be filled with insulation batts (which come in 600mm widths) or when using thicker 15mm plasterboard.

Yes. Noggings (horizontal cross-pieces between studs) provide lateral bracing, stiffen the wall, and provide fixing points for wall-mounted items like radiators, shelves and TV brackets. For a standard wall up to 2700mm high install one continuous row at mid-height (around 1200mm), which keeps noggings within the ~1350mm maximum centres used in UK practice. Add a further row for each additional ~1350mm of height on taller partitions. Use deeper 63×38mm noggings where they carry heavy fixings.

Size the structural (rough) opening to your door leaf plus the lining and a fitting tolerance. A common 838mm (2ft9in) leaf needs an opening of about 904mm — 838mm leaf + roughly 27mm of lining each side + around 12mm of packing tolerance. A 926mm (3ft) leaf needs about 992mm. Frame it with two full-height king studs, two jack studs (trimmed to door height plus header), and a header piece across the top. The sole plate is cut out after the frame is erected. Use our Door Lining Calculator to work out lining and architrave quantities.

It depends on stud spacing. British Gypsum specifies a maximum of 300mm fixing centres in the field of the board (and 200mm at external angles). On a 2400×1200mm sheet that works out at roughly 36 screws over studs at 400mm centres, or about 27 at 600mm centres. This calculator derives the figure from your chosen spacing, and you can override it in the advanced options. Use 25mm screws for single-layer 12.5mm plasterboard, or 38mm screws for double-layer boarding — always drywall screws, not wood screws.

Yes. The stud, plate/track, nogging, plasterboard, screw and tape quantities are worked out from your wall size and stud spacing, so the counts apply to a metal stud partition (light-gauge steel C-stud and track) just as they do to a timber CLS frame — only the stud material differs. For a metal frame, read the 'CLS Studs' result as your number of vertical C-studs, the head plate as ceiling track and the sole plate as floor track. Metal stud partition components are made to BS EN 14195:2014 (metal framing components for gypsum board systems). One practical difference: metal frames do not normally need cut-in timber noggings — instead, fit horizontal bracing, fixing channel or proprietary noggings only where you need a fixing point for heavy items, so you can treat the nogging figure as a maximum.

600mm centres is the standard for metal stud (light-gauge steel) partitions taking 12.5mm or 15mm plasterboard — a 1200mm board then spans three studs (both edges and the centre land on a stud). Drop to 400mm (or 300mm) centres to build a taller or stiffer wall, to suit thinner 9.5mm board, or for tiled and wet areas. British Gypsum and Knauf both publish maximum partition heights that rise as you reduce the stud centres; check the manufacturer's height table (e.g. the British Gypsum White Book GypWall data, to a deflection limit of L/240) for your exact stud depth, board layers and centres before building tall partitions.

UK metal stud (Gypframe) profiles are coded as [depth] S [gauge], e.g. 48 S 50, 70 S 50 or 92 S 50 — the first number is the stud depth in mm and the trailing number is the steel gauge in hundredths of a millimetre, so 'S 50' means 0.50mm steel (a heavier 92 S 10 is the same 92mm depth in 1.0mm steel). It is not the flange size; the flange (leg) is roughly 34–39mm. Common depths are 48, 60, 70, 92 and 146mm; deeper studs give a taller permissible wall and room for more insulation or services. The C-studs slot into a matching U-shaped floor and ceiling track (channel) of the same width. Pick the depth from the manufacturer's maximum-height table for your wall height, then enter your wall size and chosen stud spacing above to get the quantities.

Both build a sound non-loadbearing partition and both can be detailed to achieve 30, 60, 90 or 120-minute fire resistance with the right plasterboard (see Approved Document B). Light-gauge steel is non-combustible, dimensionally stable (it will not warp, twist or rot) and is the usual choice for bathrooms, utility rooms and other damp or wet areas, and for tall or commercial partitions. Timber CLS (38×89mm '4×2') is convenient for short runs, easy to fix into anywhere along the stud, and is common in domestic work. This calculator's quantities work for either — choose your stud material and the spacing to suit.