Drywall Screws
Free Drywall Screws calculator with clear step-by-step results.
About Drywall Screws
Screw count comes from two spacings multiplied together: how many studs a board crosses, and how many screws go into each stud along the board's length. Both counts add one for the end fixing, and a waste allowance covers the screws that strip, snap or vanish into the floor.
Formulas
Screws per board
Studs crossed x screws per stud, where each = floor(dimension / spacing) + 1
Total screws
Total = ceil(screws per board x boards x (1 + waste))
Worked example
With the default values below, Drywall Screws returns Screws to buy of 968. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Number of boardsaccepts 1–5,000
- 24
- Board lengthminimum 0.5 m
- 2.4 m
- Board widthminimum 0.3 m
- 1.2 m
- Stud or joist spacingaccepts 200–800 mm
- 400 mm
- Screw spacing along each studaccepts 100–400 mm
- 200 mm
- Dropped and stripped screwsaccepts 0–40 %
- 12 %
Results
- Screws to buy
- 968 screws
- Screws per board
- 36 screws
- Boxes of 1,000
- 0.97 boxes
- Board area being fixed
- 69.12 m2
Step by step
- 1Values used
- 2Screws per board
- 3Total screws
- 4Screws to buy= 968 screws
- 5Screws per board= 36 screws
- 6Boxes of 1,000= 0.97 boxes
- 7Board area being fixed= 69.12 m2
Assumptions and limits
- The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
What screw spacing should I use?
Around 200 mm on walls and 150 mm on ceilings for single-layer board. Check the board manufacturer's fixing schedule, especially for fire-rated or acoustic systems where spacing is specified.
Are the edges spaced differently?
Yes - edge fixings are usually closer and must sit at least 10 mm in from a cut edge. That detail is inside the waste allowance rather than modelled separately.