Free Drywall Calculator for Wall and Ceiling Area, Sheet Count, Waste, Screws, Tape, and Cost
Use this browser-side calculator to turn measurements and product assumptions into a practical first-pass estimate. Review the formula, replace defaults with real project data, and verify requirements before purchasing or building.
Use the calculator
How to use this calculator
1. Measure consistently
Use the units shown beside each field and recheck the dimensions that drive the calculation.
2. Replace defaults
Use actual package coverage, spacing, waste, price, product dimensions, or project ratios whenever they are known.
3. Verify before ordering
Compare the result with drawings, manufacturer data, supplier units, site conditions, and applicable requirements.
12 useful features
Room dimensions
Built into this calculator for a clearer planning workflow.
Wall perimeter area
Built into this calculator for a clearer planning workflow.
Opening subtraction
Built into this calculator for a clearer planning workflow.
Optional ceiling
Built into this calculator for a clearer planning workflow.
Custom sheet size
Built into this calculator for a clearer planning workflow.
Waste allowance
Built into this calculator for a clearer planning workflow.
Whole-sheet count
Built into this calculator for a clearer planning workflow.
Screws per sheet
Built into this calculator for a clearer planning workflow.
Rough tape allowance
Built into this calculator for a clearer planning workflow.
Optional sheet cost
Built into this calculator for a clearer planning workflow.
Local history
Built into this calculator for a clearer planning workflow.
Copy/download/print/reset
Built into this calculator for a clearer planning workflow.
Formula and reference table
| Concept | Formula / meaning | Planning note |
|---|---|---|
| Wall area | 2 × (length + width) × height − openings | Room perimeter walls |
| Ceiling area | length × width | Optional |
| Sheet count | ceil(total area ÷ sheet area × waste factor) | Whole sheets |
| Screw estimate | sheets × screws per sheet | User-adjustable planning ratio |
Pre-order checklist
0 / 5 complete
Quick knowledge check
What is the safest way to use a construction calculator?
Microlearning guide
Geometry is one layer
A correct area, volume, spacing, or slope formula does not replace structural, product, installation, or code requirements.
Whole units matter
Sheets, bags, boards, rolls, bundles, and stock pieces are purchased as discrete units, so planning often requires rounding upward.
Assumptions drive results
Waste, spacing, product coverage, price, pitch, dimensions, or layout choices can change an estimate more than extra decimal places.
Examples and practical uses
Early planning
Compare quantity or cost scenarios before requesting material quotes.
Purchase cross-check
Compare the result with package coverage, stock lengths, supplier recommendations, and project drawings.
Formula review
Use the reference table to independently reproduce the main arithmetic.
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Frequently asked questions
Does this optimize sheet orientation?
No. It estimates by area. A real board layout can use more or fewer sheets depending on orientation, seams, offcuts, framing, and room shape.
Should I subtract every opening?
Large doors and windows can be subtracted, but small openings may not reduce purchased sheets because surrounding pieces still come from full boards.
Does the tape estimate map every seam?
No. It is a rough allowance derived from covered area, not a joint-by-joint seam layout.
Can I include a ceiling?
Yes. The ceiling option adds room length × width to the wall area.
Does this calculate drywall mud?
No. Use the dedicated Drywall Mud Calculator for joint-compound planning.