Drywall — also called sheetrock — is sold by the sheet but estimated by the square foot. This calculator converts room dimensions into sheet counts for every common size, then adds the joint compound, tape, and screws you will need to finish the job.
Working from a linear wall measurement instead of room dimensions? See Linear Feet for Drywall.
About pricing on this page
This calculator is intentionally price-light. Absolute dollar figures are deliberately omitted because they vary too widely by region, brand, and installer to be useful as planning estimates. The relative-comparison tables below show how options stack up against each other — which is the durable, actionable information. For a real budget, get two or three written quotes from local suppliers and contractors after they have seen the job.
Drywall Sheet Calculator
Enter room dimensions and ceiling height. Results give sheet counts, mud, tape, screws, and cost.
The Drywall Sheet Formula
Wall Area = Room Perimeter ft × Ceiling Height ft
Ceiling Area = Length ft × Width ft
Sheets = ((Wall + Ceiling − Openings) × (1 + Waste %)) ÷ Sq Ft per Sheet
Using room perimeter rather than adding four separate walls is faster and less error-prone. Perimeter of a rectangular room is simply (length + width) × 2.
Worked example: A 12 × 14 ft bedroom, 8 ft ceilings, one doorway. Perimeter is (12 + 14) × 2 = 52 ft. Walls: 52 × 8 = 416 sq ft. Ceiling: 12 × 14 = 168 sq ft. Total 584 sq ft, minus 21 sq ft for the door = 563 sq ft. Add 10% waste = 619 sq ft. In 4 × 8 sheets: 619 ÷ 32 = 19.3 → 20 sheets. In 4 × 12 sheets: 619 ÷ 48 = 12.9 → 13 sheets.
Drywall Sheet Sizes and Coverage
| Sheet Size | Sq Ft | Weight (1/2 in) | Sheets per 500 Sq Ft | Price Each | Best For |
|---|---|---|---|---|---|
| 4 × 8 ft | 32 | 54 lbs | 16 | Reference only | Small rooms, DIY, tight access |
| 4 × 9 ft | 36 | 61 lbs | 14 | Reference only | 9 ft ceilings, vertical hang |
| 4 × 10 ft | 40 | 68 lbs | 13 | Reference only | Standard rooms, fewer seams |
| 4 × 12 ft | 48 | 82 lbs | 11 | Reference only | Long walls, pro crews |
Larger sheets mean fewer seams and less taping labor, which is where most of the finishing cost lives. But a 4 × 12 sheet of 5/8 in drywall weighs over 100 lbs and cannot be maneuvered up a stairwell by one person.
Drywall Thickness — Which to Use Where
| Thickness | Type | Weight per Sq Ft | Price Premium | Use |
|---|---|---|---|---|
| 1/4 in | Flexible | 0.8 lbs | Baseline | Curved walls, skim over old plaster |
| 3/8 in | Standard | 1.2 lbs | −5% | Repairs, double-layer applications |
| 1/2 in | Standard | 1.7 lbs | Standard | Most walls and ceilings |
| 1/2 in | Lightweight | 1.3 lbs | +10% | Ceilings, easier DIY handling |
| 1/2 in | Moisture / green board | 1.8 lbs | +30% | Bathrooms, laundry, kitchens |
| 5/8 in | Type X fire-rated | 2.2 lbs | +25% | Garages, party walls, code areas |
| 5/8 in | Soundproof | 3.5 lbs | +250% | Home theaters, shared walls |
Building codes usually require 5/8 in Type X on garage walls and ceilings shared with living space, and on ceilings where framing is spaced 24 in on center. Check your local code before ordering 1/2 in for those areas.
Finishing Materials per 500 Square Feet
| Material | Quantity | Coverage | Cost |
|---|---|---|---|
| Joint compound (all-purpose) | 1 × 5 gal bucket | ~500 sq ft | Reference only |
| Paper joint tape | 1 × 250 ft roll | 400–500 sq ft | Reference only |
| Drywall screws (1-1/4 in) | 2–3 lbs | ~32 screws/sheet | Reference only |
| Corner bead | Per outside corner | 8–10 ft each | Reference only |
| Sanding sponges / screens | 3–5 pieces | — | Reference only |
| Primer (PVA drywall) | 1.5 gal | 300–350 sq ft/gal | Reference only |
Corner bead is sold by the piece and measured in linear feet, not square feet. Count every outside corner in the room and buy one length per corner, rounding up to the next stock size.
Drywall Installation Cost
| Scope | Cost per Sq Ft | Per 4×8 Sheet | 12×14 Room (584 sq ft) |
|---|---|---|---|
| Materials only (DIY) | Reference only | Reference only | Reference only |
| Hang only | Reference only | Reference only | Reference only |
| Hang + tape + Level 4 | Reference only | Reference only | Reference only |
| Level 5 finish | Reference only | Reference only | Reference only |
| Demo of existing drywall | Reference only | Reference only | Reference only |
Level 4 is the standard residential finish suitable for flat and eggshell paint. Level 5 adds a full skim coat and only pays off under gloss paint or raking side light, where every seam would otherwise show.
Forgetting the Ceiling
In a 12 × 12 room with 8 ft ceilings, the ceiling is 144 sq ft against 384 sq ft of wall — 27% of the total. Estimating walls only leaves you four or five sheets short. Ceiling drywall is also the harder half of the job: it requires a lift or a second person, and most builders use lightweight 1/2 in board specifically to make overhead hanging manageable.
Deducting Every Small Opening
Meticulously subtracting each outlet, switch, and small window produces an order that is short in practice. The material cut out of a wall for a 14 × 20 inch window offcut is almost never large enough to use elsewhere. Deduct only openings above roughly 20 sq ft, and let the smaller ones absorb into the waste allowance where they belong.
Buying 4 × 12 Sheets Without Checking Access
A 12-foot sheet cannot turn a tight stairwell corner or pass through a standard 32-inch doorway at an angle. Measure the delivery path before ordering long sheets for an upstairs room. Crews routinely arrive with 12 ft board for a second-floor bedroom and end up cutting every sheet down on the driveway, which defeats the entire purpose of buying the larger size.
Using Standard Board in Wet or Fire-Rated Areas
Bathrooms, laundry rooms, and garages have specific requirements. Standard board behind a shower surround will fail as the paper facing wicks moisture and the gypsum core softens. Garage walls adjoining living space almost always require 5/8 in Type X by code. Getting this wrong means either a failed inspection or a tear-out down the line.
About these price ranges
Pricing varies widely by region, season, project size, and site conditions. Treat every figure on this page as a planning estimate for budgeting only — not as a quote. Coastal metro markets commonly run 20–40% above national ranges while rural inland markets can fall 10–20% below. Always collect at least three written quotes from local contractors before committing to a budget.
Unsourced estimates: All dollar figures on this page. The relative-comparison tables above are sourced from general trade conventions and the labour-plus-material methodology used in industry references, not from a specific published price index. These are informed planning figures rather than data drawn from a published price index, and they carry a correspondingly wider margin of error.