TapeMath
Home › Tools › On-center layout

On-center layout tables

How many studs, joists or deck boards a wall needs, and where every mark lands — at 12, 16, 19.2 and 24 inch on-center spacing.

12" on center
6 ft wall · 7 studs8 ft wall · 9 studs10 ft wall · 11 studs12 ft wall · 13 studs14 ft wall · 15 studs16 ft wall · 17 studs18 ft wall · 19 studs20 ft wall · 21 studs22 ft wall · 23 studs24 ft wall · 25 studs26 ft wall · 27 studs28 ft wall · 29 studs30 ft wall · 31 studs32 ft wall · 33 studs34 ft wall · 35 studs36 ft wall · 37 studs38 ft wall · 39 studs40 ft wall · 41 studs
16" on center
6 ft wall · 6 studs8 ft wall · 7 studs10 ft wall · 9 studs12 ft wall · 10 studs14 ft wall · 12 studs16 ft wall · 13 studs18 ft wall · 15 studs20 ft wall · 16 studs22 ft wall · 18 studs24 ft wall · 19 studs26 ft wall · 21 studs28 ft wall · 22 studs30 ft wall · 24 studs32 ft wall · 25 studs34 ft wall · 27 studs36 ft wall · 28 studs38 ft wall · 30 studs40 ft wall · 31 studs
19.2" on center
6 ft wall · 5 studs8 ft wall · 6 studs10 ft wall · 8 studs12 ft wall · 9 studs14 ft wall · 10 studs16 ft wall · 11 studs18 ft wall · 13 studs20 ft wall · 14 studs22 ft wall · 15 studs24 ft wall · 16 studs26 ft wall · 18 studs28 ft wall · 19 studs30 ft wall · 20 studs32 ft wall · 21 studs34 ft wall · 23 studs36 ft wall · 24 studs38 ft wall · 25 studs40 ft wall · 26 studs
24" on center
6 ft wall · 4 studs8 ft wall · 5 studs10 ft wall · 6 studs12 ft wall · 7 studs14 ft wall · 8 studs16 ft wall · 9 studs18 ft wall · 10 studs20 ft wall · 11 studs22 ft wall · 12 studs24 ft wall · 13 studs26 ft wall · 14 studs28 ft wall · 15 studs30 ft wall · 16 studs32 ft wall · 17 studs34 ft wall · 18 studs36 ft wall · 19 studs38 ft wall · 20 studs40 ft wall · 21 studs
The same math, offline

Every calc, on your tape measure — even with no signal.

TapeMath for iPhone runs this exact engine offline, adds rafters, stairs, studs, pitch and a paperless tape, and the key layout your thumbs already know. $9.99 once — no subscription, ever.

See the app
Coming soon — TapeMath is in final App Review. Meanwhile, use the free web calculator →