Studs on a Wall at a Given Spacing

Also known as how many studs · studs 16 on center · joist count

N=Ls+1N = \frac{L}{s} + 1

Enter your known values, leave one input blank, and solves for the missing one. Try different units for next level excitement!

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The plus one is the whole formula. Studs at 16 in on centre across a 24 ft wall give 288/16=18288/16 = 18 bays, and 18 bays need 19 studs, because you have to close the far end as well as start the near one. Fence posts, joists, deck boards and balusters all count the same way, and forgetting the last one is the classic off-by-one of the trades.

What this gives you is the field count only. Real walls need more: two or three studs at each corner depending on the corner detail, jack and king studs at every opening, cripples above and below, and extra backing wherever cabinets or grab bars land. Framers usually take the field count, add the openings by hand, and then throw in a few percent for crooked stock that gets culled.

Spacings are conventional rather than arbitrary. Imperial framing uses 16 in or 24 in on centre so that 4 ft sheet goods break on a stud every time; metric framing uses 400 mm or 600 mm for the same reason with 1200 mm sheets. Mixing a metric spacing with imperial sheets is a good way to end up with unsupported edges.

Studs on a Wall at a Given Spacing
N=Ls+1N = \frac{L}{s} + 1
Where
  • NN= Members required
  • LL= Run length
  • ss= On-centre spacing