Stud calculator
Enter a wall length and stud spacing and this counts the studs, the plate stock, and the board feet. Add corners and it counts two studs per standard corner, or one per California corner. Switch to a rake wall for the gable stud count and the shortest and tallest lengths. The math is ported from the CutOnce app's tested wall-stud and rake-wall solvers.
Updated
Field studs are the on-center run: floor(length / spacing) plus one on an exact fit, or plus two when the wall does not divide evenly (the far end gets its own stud), never fewer than two. Each corner adds two studs, or one on a California corner. Waste rounds the total up. Plate stock is the wall length times two plates, or three with a double top plate.
- Field studs
- 19
- Corner studs
- 0
- Plate stock
- 72.0 lin ft
- Total stud length
- 152.0 ft
- Board feet
- 101.3 bf
How stud count works
A wall gets one stud at every on-center mark, plus a stud at each end. So the count is the wall length divided by the spacing, plus one when the length lands exactly on a mark, or rounded up plus one more when it does not, because the far end still needs its own stud. Never fewer than two. A 16 foot wall at 16 inches on center is 12 intervals, so 13 field studs. Corners add to that field count, and the calculator adds them for you.
A worked example
A 24 ft wall at 16 in on center, 8 ft studs with a double top plate and two standard corners. Here is the full count and the material it comes to.
| Field studs | 19 | 288 in / 16, + 1 |
| Corner studs | 4 | 2 corners x 2 |
| Total studs | 23 | field + corners |
| Plate stock | 72 lin ft | bottom + 2 top plates x 24 ft |
| Total stud length | 184 ft | total studs x 8 ft |
| Board feet | 122.7 bf | 2x4 x 8 ft, per stud |
How corners add up
The field studs march along the wall. Each corner or wall intersection adds two studs for a standard three-stud corner or one for a California two-stud corner. Enter the corners and the calculator adds them to the field count. A waste factor rounds the whole count up when you want a cushion.
Field studs by wall length
Field stud count for common wall lengths at 16 and 24 inches on center. Add corner studs on top.
| Wall length | 16 in OC | 24 in OC |
|---|---|---|
| 8 ft | 7 | 5 |
| 10 ft | 9 | 6 |
| 12 ft | 10 | 7 |
| 16 ft | 13 | 9 |
| 20 ft | 16 | 11 |
| 24 ft | 19 | 13 |
Rake and gable walls
A rake wall (the triangular wall under a gable, or a shed-roof end) has studs that grow along the run at the roof pitch. This is where a stud calculator earns its keep: every stud is a different length, and cutting them off a story pole is slow and error-prone. Enter the pitch, the run, and the short-wall height, and the app steps each stud up by the pitch and lays out the cut list.
A 12 ft run at a 6/12 pitch on an 8 ft short wall: 10 studs, the shortest at the 8 ft short-wall height and the tallest at the ridge end.
| Studs | 10 |
| Shortest | 8 ft 0 in |
| Tallest | 14 ft 0 in |
Common questions
- How many studs do I need for a 24 foot wall?
- Nineteen field studs at 16 inches on center: a 24 foot wall is 288 inches, which is 18 on-center intervals, plus one is 19. At 24 inches on center it drops to 13. Then add two studs for each standard corner, or one for a California corner, which the calculator does once you enter the corners.
- What is the difference between 16 and 24 inch on center?
- The spacing between stud centers. Sixteen inch spacing puts more studs in the wall (stiffer, standard for most load-bearing walls and where drywall edges need backing); 24 inch is allowed for many walls under the code's advanced-framing provisions and uses less lumber. The calculator does either; check your plan and local code for which applies.
- Does this include the plates and corners?
- Yes. It counts the field studs, adds two studs per standard corner (one for a California corner), estimates the plate stock (two plates, or three with a double top plate), and totals the stud length and the board feet.
- How do I figure gable or rake wall studs?
- Switch the calculator to rake wall. Each stud grows along the run at the roof pitch, so the calculator steps from the short-wall height up to the tall end and gives the count with the shortest and tallest lengths. The app prints the full schedule, every stud numbered with its own cut length.
- Why 'plus one' on the stud count?
- Because a wall has a stud on both ends. Divide the length by the spacing and you have counted the on-center bays, not the studs; add one for the closing end stud. When the wall does not land exactly on a mark, the far end still needs its own stud past the last full mark, so a non-exact wall gets one more (rounded up plus one). Either way, the far end is never left without a stud to nail to.
Count the studs, cut the rake
CutOnce counts the wall studs like this page, then does the part that is actually hard: the rake wall, stepping every gable stud up the pitch and printing a numbered cut list, plus the plates and the wall elevation.
Free to download, with a 7-day trial of everything. The web calculator is the teaser; the app prints the cut list.
See also