Woodworking & Construction Calculators

Carpentry & framing

Wall Framing Stud Estimator (16 in and 24 in O.C.)

Pick 16 in or 24 in on-center spacing. The tool places one stud at the start, one on every O.C. mark and one closing the far end, then adds two studs per opening for the jack (trimmer) studs under the header.

Inputs

Units
ft

Doors and windows, as a whole number. Each adds two extra studs in this estimate.

%

Terms of Service

Results

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Calculation method

Layout studs land on O.C. marks, so a 16 ft wall at 16 in O.C. is 13 studs before openings. When the wall is not a whole number of spacings, one more stud closes the far end: a 10 ft wall at 16 in O.C. needs 9. Each door or window adds two studs, one jack (trimmer) per side; layout studs that fall inside the opening stay in the count and cover the king and cripple studs. Plates are three times the wall length.

Exact formula

studs = ceil((length_in − 1.5) / OC) + 1 + 2 × openings. The 1.5 in is one stud thickness: the end stud closes a leftover space no wider than itself. Three plates (bottom + double top) × wall length. Waste rounds the stud count up.

Metric walls

Length converts to metres; 16 in and 24 in O.C. stay as framing conventions (406 mm and 610 mm).

Frequently asked questions

Does 24 in O.C. use fewer studs?

Yes, but sheathing, drywall and openings still need blocking. Check the wall type and code.

Are corner studs included?

The count includes the first stud at the wall start and the stud that closes the far end. Three-stud corners and intersecting walls need extras this tool does not add.

What about headers?

Order header stock separately. This count is vertical studs and plate lineal footage.

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