Drywall Calculator
Sheets, mud, screws, and tape — the whole hang list. Free, instant, and private — everything runs on your device.
Your drywall estimate
- Total area
- 472 sq ft
- Joint compound (typical)
- ~5 gal
- Drywall screws (typical)
- ~5 lb
- Joint tape (typical)
- ~189 ft
- Estimated cost (sheets)
- $238
Sheet count is exact; compound, screws, and tape use standard rules of thumb — round up and keep the receipt. Bigger 4×12 sheets mean fewer seams to tape, but they're heavier and harder to handle solo.
Hanging drywall is the fast part; buying the right amount is where projects stall. Order sheet count off a rough guess and you're back at the store for two more, cutting into a Saturday. This calculator gives you an exact sheet count from your room dimensions and sheet size, then rounds in a waste allowance for the cuts around windows, doors, and outlets that never land on a clean seam.
It also lists the consumables people forget until the walls are up: joint compound, drywall screws, and paper tape. Those numbers use standard estimator rules of thumb — round up and keep the receipt — so your first trip is your only trip.
How it works
No black box — this is the exact math the calculator runs.
- Wall area = 2 × (length + width) × ceiling height; add length × width if you're doing the ceiling.
- Sheets = total area × (1 + waste) ÷ sheet coverage (32 sq ft for 4×8, 48 for 4×12), rounded up.
- Joint compound ≈ one 4.5-gallon box per ~475 sq ft (taping plus three coats).
- Screws ≈ 1 lb per 100 sq ft; joint tape ≈ 0.4 linear feet per square foot.
- Cost = sheets × your price per sheet (compound, screws, and tape priced separately).
Last reviewed July 24, 2026 · Rooms & Organization
Frequently asked questions
How many sheets of drywall do I need for a 12x10 room?
The four walls at 8 feet are about 352 sq ft — roughly 13 sheets of 4×8 with a 10% waste allowance. Add the ceiling (another 120 sq ft) and you're near 17 sheets. Using 4×12 sheets on long walls drops the count and the number of seams.
Should I use 4x8 or 4x12 drywall sheets?
4×12 sheets cover more and create fewer horizontal seams to tape and finish — a smoother wall with less work — but they're heavy and awkward to carry and lift solo. 4×8 sheets are the practical choice for one person or tight stairwells.
How much joint compound and tape do I need?
As a rule of thumb, one 4.5-gallon box of all-purpose compound covers about 475 sq ft through taping and three coats, and you'll use roughly 0.4 feet of tape per square foot of drywall. Buy a little extra — running out mid-coat means an awkward restart.
Do I subtract doors and windows from the drywall count?
For estimating, most people don't — the offcuts around openings rarely yield full usable pieces, and the waste factor absorbs them. This calculator keeps the openings in the area and adds waste, which keeps you from coming up short.