Drywall Calculator
Enter your measurements
Extra to cover cuts, breakage, and mistakes.
Results
- 4×8 sheets14 sheets
- 4×12 sheets9alternative size
- Joint compound1 boxes
- Screws2 lb
- Tape154 ft
Estimated cost
per 4×8 drywall sheet (material)
Material is per 4×8 sheet of standard 1/2-inch board; 5/8-inch Type X, moisture-resistant, and mold-resistant panels run toward the high end. Installed cost covers hang, tape, and finish to a Level 4 (roughly $1.50–$3.50 per sq ft) including labor and consumables, but not priming or painting.
Estimate only — prices vary by region, supplier, and season. Get a local quote before buying.
This drywall calculator turns room dimensions into a complete material list — sheets, joint compound, tape, and screws — in one pass. Enter your total wall length, wall height, and any ceiling area, pick a waste percentage, and you get quantities ready to hand to a supplier or drop into a budget. The headline output is drywall sheets in both 4×8 and 4×12 formats, so you can see which size fits your studs and minimizes seams and cuts. Drywall is sold by the sheet. Standard 4×8 panels cover 32 square feet each; 4×12 panels cover 48 square feet and cut down on seams over tall or long walls, but they are heavier and awkward to hang solo. Suppliers usually sell in lifts (often 30 to 50 sheets), while home centers also sell single sheets off the rack. A 10% waste factor suits a plain rectangular room; bump it to 15% when the space has many windows, doors, soffits, or angled ceilings that force more cuts and offcuts you can't reuse.
How it’s calculated
Sheets = Wall + ceiling area ÷ sheet size (4×8 = 32 sq ft, 4×12 = 48 sq ft), plus waste.
Worked example
For a room with 48 linear feet of walls at 8 feet tall and a 10% waste allowance, the calculator returns 14 standard 4×8 sheets or 9 of the longer 4×12 panels for the same 384 square feet of wall. Alongside the board count you get 1 box of joint compound, 2 lb of screws, and 154 feet of tape — a full materials ticket before your first trip to the lumber yard.
Inputs
- Total wall length
- 48 ft
- Wall height
- 8 ft
- Waste / overage
- 10 %
Result
- 4×8 sheets
- 14 sheets
- 4×12 sheets
- 9
- Joint compound
- 1 boxes
- Screws
- 2 lb
- Tape
- 154 ft
- Estimated material cost
- $168 – $252
Materials & pricing near you
Drywall is priced per sheet, sold individually at home centers or by the lift through drywall distributors. Half-inch regular 4×8 board sits at the low end, while 5/8-inch Type X fire-rated panels — required by code in garages and on garage-to-house separation walls — cost more per sheet. Moisture-resistant green board and mold-resistant panels carry a further premium. Dense metro markets generally run higher than rural areas, and pricing can spike after hurricanes or hard freezes when rebuilding demand surges. Specialty yards often set delivery minimums around half a lift, with a flat delivery charge on top, so single-room jobs are usually cheaper to carry from a big-box store. Permits are rarely needed for drywall replacement alone, though a gut renovation that opens walls may trigger an inspection.
Frequently asked questions
How do I measure a room for drywall?
Add the lengths of all walls and multiply by the ceiling height for gross wall square footage, then add the ceiling area (length × width) if you're drywalling it too. Subtract large openings — a standard door is about 20 sq ft and a window 10–15 sq ft — to get net area. On small rooms many estimators skip those deductions and treat the openings as built-in waste, since the offcuts around them are usually too small to reuse.
Should I use 4×8 or 4×12 drywall sheets?
4×12 sheets hung horizontally create fewer butt seams on 8-foot walls, which means less taping and finishing. They cost a bit more per sheet but often save labor. The trade-off is weight: a 4×12 half-inch panel runs around 77 lb, so it's a two-person lift or a panel jack. A 4×8 sheet is roughly 54 lb and far easier to maneuver in closets, stairwells, and other tight spots.
How much joint compound do I need?
A rough rule is one 4.5-gallon box (about 62 lb) of all-purpose pre-mixed compound per 500–600 square feet of drywall. Finishing is done in three coats — a tape-embedding coat, a fill coat, and a finish coat — so real usage depends on your technique and how smooth a finish you want. Lightweight finishing compound stretches further on the final coats but shouldn't be used to set tape.
What thickness of drywall is standard?
Half-inch board is the residential standard for most interior walls and ceilings. Five-eighths-inch Type X is code-required in garages and on walls shared with an attached garage, and is common on ceilings in multifamily construction for fire rating. Three-eighths-inch panels are thinner and used mainly for curved walls or as a skin-over layer on top of existing drywall to avoid a full tear-out.