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Sheets by wall length
| Wall length × 8 ft | 4 × 8 sheets | 4 × 12 sheets |
|---|---|---|
| 60 ft | 17.0 | 11.0 |
| 90 ft | 25.0 | 17.0 |
| 120 ft | 33.0 | 22.0 |
| 150 ft | 42.0 | 28.0 |
| 180 ft | 50.0 | 34.0 |
| 240 ft | 66.0 | 44.0 |
Includes 10% waste, no openings deducted.
A 4 × 8 sheet covers 32 sq ft, 4 × 10 covers 40 and 4 × 12 covers 48. Longer sheets mean fewer joints to tape, but they are heavy to carry down basement stairs. Many builders use moisture- and mold-resistant board below grade.
Installed cost
HomeAdvisor lists drywall installation at $1.50–$3 per square foot and panels around $20 each. Trusscore's figure for a complete hang, tape, mud, sand, prime and paint job is $3.00–$5.50 per square foot.
Measuring the example basement
The worked examples on these pages use the same basement so you can follow one project through every material: 32 × 26 ft (832 sq ft of floor), 116 ft of perimeter wall, and 7′ 8″ from the slab to the underside of the joists. About 120 sq ft around the furnace and water heater stays unfinished, and the finished room has one door (about 20 sq ft) and two small windows (about 10 sq ft each).
Worked example
116 ft of wall at 8 ft is 928 sq ft; less 40 sq ft of openings leaves 888 sq ft. With 10% waste that is 977 sq ft, or 31 sheets of 4 × 8 board. The 712 sq ft ceiling adds 25 more sheets. At HomeAdvisor's $1.50–$3 per sq ft, hanging all 1,600 sq ft costs about $2,400–$4,800; at Trusscore's full-finish $3.00–$5.50 it is $4,800–$8,800.
Mistakes that change the count
- Measuring the outside of the foundation. Interior walls stand 2–4 in in from the concrete once foam and studs go in, which shortens every wall slightly. The difference is small; round up rather than trim the order.
- Forgetting soffits. Boxes around ducts and beams add wall and ceiling surface that never shows on a floor plan.
- Skipping waste. Basements are full of cut-outs for posts, panels and pipes. 10% waste is a sensible default for sheet goods.
- Buying for the floor, not the walls. Wall area in a basement is often larger than floor area: here the walls are 928 sq ft at 8 ft against 832 sq ft of floor.
Ordering and delivery tips
- Round up to full units: sheets, boxes, gallons and bags are not sold in fractions.
- Check the basement stair turn before buying 12-ft drywall or long trim; it may not fit down the stairs.
- Let flooring acclimate in the basement for the time printed on the carton.
- Keep a few spare boxes or sheets of the same batch for repairs.
- Store drywall and wood off the slab on blocks.
Common questions
How many sheets of drywall for a basement?
Wall length × height ÷ 32 for 4 × 8 sheets, plus about 10% for waste. 120 ft of 8-ft wall needs about 33 sheets.
What thickness of drywall for basement walls?
½ in is standard for walls and ceilings. Check local fire-separation rules near the furnace and under stairs.
Related calculators
Sources
- https://www.homeadvisor.com/cost/basements/
- https://trusscore.com/blog/the-cost-to-finish-a-basement-in-2024.html
- https://www.blockrenovation.com/guides/basement-remodel-cost-per-square-foot-2026