How the stud wall calculator works
A stud wall is a frame of vertical studs fixed between a sole plate on the floor and a head plate on the ceiling, braced with horizontal noggins. The calculator counts each part and converts it into timber lengths:
Door openings get a pair of extra studs and a head piece. Plasterboard is based on 2400 × 1200mm sheets with 10% extra for cuts.
Building a stud wall: step by step
- Mark the wall position on the floor and use a laser or plumb line to transfer it to the ceiling. Fix the head plate into joists, or into noggins between them if the wall runs parallel.
- Fix the sole plate to the floor, leaving gaps for door openings.
- Cut studs to fit tightly between the plates and fix at your chosen centres, starting from one wall.
- Add noggins at mid-height (staggered so you can screw through the studs) and extra noggins for heavy fixings.
- Run cables and pipes, add insulation, then board each side with joints staggered.
Worked example: a 3.6m wall with a door
A 3.6m × 2.4m partition at 400mm centres needs 3.6 ÷ 0.4 + 1 = 10 studs, plus 2 for the door opening = 12 studs. In total, with the two 3.6m plates, one row of noggins and a door head, that's about 40.6m of timber. Add 10% for offcuts and it's 44.7m, or 15 lengths of 3m 38 × 89mm CLS. Boarding both sides takes 7 sheets of 2400 × 1200mm plasterboard. The calculator doesn't deduct the doorway, which covers the cutting waste round it. Filling the frame with acoustic insulation takes about 8.6m².
The "Next for this job" links carry the boarded area straight into the plaster, skirting and paint calculators, so you can price the whole wall.
Choosing timber and board
- 38 × 89mm CLS is the standard for most partitions: straight, planed and easy to work. Use 38 × 63mm only for short, low walls or boxing-in.
- 400mm centres suit 12.5mm plasterboard and tiled walls. 600mm centres use less timber but need 15mm board and feel less solid.
- Plasterboard types: standard (grey or white face) for most rooms, moisture-resistant (green) for bathrooms and kitchens, acoustic (blue) for quieter bedrooms, and fire-rated (pink) where Building Regulations require it.
- Heavy fixings: add extra noggins where wall cupboards, TVs, radiators or basins will hang, and photograph the frame before boarding so you know where they are.
Common stud wall mistakes
- Fixing to nothing. A head plate fixed only to plasterboard ceiling will move. Find the joists, or fit noggins between them where the wall runs parallel.
- Forced-in studs. Studs hammered in too tight bow the plates and crack plaster later. Cut them to a snug, not forced, fit.
- Forgetting services. Plan sockets, switches and any pipework before boarding. Cables should run in the safe zones or be protected, and electrical work must meet Part P.
- Creating a room without checking the rules. A new bedroom may need an escape window, ventilation and fire-safe routes. Our stud wall guide covers these.
Building a whole new room? The stud wall room planner runs through framing, plastering, skirting and painting in order. For plasterboard on existing walls, use the plasterboard calculator.