Drywall Calculator — Sheets, Screws, Mud & Tape
Who this is for: For contractors bidding a hang-and-finish and DIYers finishing a basement — how many sheets to order and what the fastener and mud reality looks like.
Room dimensions in — sheets by size (4×8/4×10/4×12), screws, tape, and joint compound out, with door and window deductions and a waste factor.
Quick answer: Sheets = net area × 1.10 ÷ sheet area (4×8 = 32 sf). A 12×14 room at 8 ft is 416 sf of wall ≈ 13 sheets, 500 screws, 183 ft of tape, and 48 lb of compound (1 door + 2 windows deducted) for a level-4 finish.
−20 sf each
−15 sf each
| Sheet areas | 4×8 = 32 sf · 4×10 = 40 · 4×12 = 48 |
|---|---|
| Deductions | 20 sf/door · 15 sf/window |
| Screws | ≈1.1 per sf |
| Compound | ≈65 lb per 500 sf (level 4) |
How does the drywall calculator count sheets?
Wall area is the room's perimeter × height — 2 × (length + width) × height — plus the ceiling if you're boarding it, minus 20 sf per door and 15 sf per window. Sheets = net area × waste ÷ sheet area: 4×8 sheets cover 32 sf, 4×10s 40 sf, 4×12s 48 sf, and 10% waste is the standard allowance for cutouts and the offcuts that don't fit anywhere. The consumables use level-4 finish rules of thumb: about 1.1 screws per square foot (rounded to the hundred), half a foot of tape per square foot, and roughly 65 pounds of ready-mixed compound per 500 square feet. A 12×14 room at 8 feet is 416 sf of wall — with a door and two windows deducted, 13 sheets of 4×8 with waste and 500 screws, and about 48 lb of mud.
Common uses
- Ordering sheets for a hang job without a third hardware-store run
- Bidding drywall labor off real sheet counts
- Planning mud and tape purchases by finish level
- Comparing 4×8 vs 4×12 sheet strategies on tall walls