🧱 Drywall Calculator
Calculate drywall sheets, joint compound, tape, and screws for your project.
Quick Formulas
Sheets Needed
Sheets = (Total Wall Area ÷ Sheet Size) × Waste Factor
Common Sheet Sizes
| Size | Square Feet | Best For |
|---|---|---|
| 4' × 8' | 32 sq ft | Residential, easy handling |
| 4' × 10' | 40 sq ft | 9' ceilings, fewer joints |
| 4' × 12' | 48 sq ft | Commercial, long runs |
| 4' × 14' | 56 sq ft | High ceilings |
Coverage Calculations
Wall Area
Wall Area = Perimeter × Height
Example: 12' × 14' room with 8' ceilings
- Perimeter = (12 + 14) × 2 = 52 linear feet
- Wall Area = 52 × 8 = 416 sq ft
- Sheets (4×8) = 416 ÷ 32 = 13 sheets + waste
Ceiling Area
Ceiling Area = Length × Width
Example: 12' × 14' room
- Ceiling = 12 × 14 = 168 sq ft
- Sheets (4×8) = 168 ÷ 32 = 5.25 = 6 sheets
Deductions for Openings
| Opening | Typical Size | Deduction |
|---|---|---|
| Standard door | 3' × 7' | 21 sq ft |
| Double door | 6' × 7' | 42 sq ft |
| Window (average) | 3' × 4' | 12 sq ft |
| Large window | 4' × 5' | 20 sq ft |
Pro Tip
For residential, many estimators don't deduct for standard doors and windows — the "extra" drywall covers waste from cutting. Only deduct for very large openings.
Waste Factors
| Situation | Waste Factor |
|---|---|
| Simple rectangular rooms | 5-10% |
| Rooms with many corners | 10-15% |
| Cathedral/vaulted ceilings | 15-20% |
| Complex shapes, angles | 20-25% |
Materials Needed
Joint Compound (Mud)
| Type | Coverage | Notes |
|---|---|---|
| All-purpose (premixed) | ~60-80 sq ft per gallon | Multiple coats |
| Lightweight | ~80-100 sq ft per gallon | Easier sanding |
| Setting compound | Varies | Time-sensitive |
Rule of thumb: 1 gallon per 100 sq ft of drywall (all coats)
Tape
| Type | Roll Length | Coverage |
|---|---|---|
| Paper tape | 500 ft | ~500 linear ft of joints |
| Mesh tape | 300 ft | ~300 linear ft of joints |
Estimating tape:
- Each 4×8 sheet has ~20 linear feet of edges
- Calculate: (Total sheets × 20 LF) ÷ 2 = tape needed
Screws
| Application | Spacing | Screws per Sheet |
|---|---|---|
| Walls | 16" OC framing | ~32 screws |
| Ceilings | 12" OC or per code | ~40 screws |
| Fire-rated | Per spec | Often more |
Rule of thumb: 1 lb of screws per 500 sq ft
Drywall Types
| Type | Thickness | Use |
|---|---|---|
| Standard (white) | 1/2" | Most walls |
| Lightweight | 1/2" | Easier handling |
| Fire-rated (Type X) | 5/8" | Garages, rated assemblies |
| Moisture-resistant (green) | 1/2", 5/8" | Bathrooms, kitchens |
| Mold-resistant (purple) | 1/2", 5/8" | High-moisture areas |
| Soundboard | 5/8" | Sound isolation |
| Ceiling board | 1/2" | Sag-resistant for ceilings |
Quick Reference Table
| Room Size | Walls (8' ceiling) | Ceiling | Total Sheets (4×8) |
|---|---|---|---|
| 10' × 10' | 10 sheets | 4 sheets | 14 sheets |
| 10' × 12' | 11 sheets | 4 sheets | 15 sheets |
| 12' × 12' | 12 sheets | 5 sheets | 17 sheets |
| 12' × 14' | 13 sheets | 6 sheets | 19 sheets |
| 14' × 16' | 15 sheets | 7 sheets | 22 sheets |
Includes ~10% waste, no deductions for openings
Sample Material List
For a 12' × 14' room with 8' ceilings:
| Material | Quantity | Notes |
|---|---|---|
| 1/2" Drywall (4×8) | 19 sheets | Walls + ceiling |
| Joint compound | 5 gallons | All-purpose |
| Paper tape | 1 roll | 500 ft roll |
| Drywall screws | 2 lbs | 1-1/4" coarse thread |
| Corner bead | 32 LF | If needed |
Labor Estimates
| Task | Production Rate |
|---|---|
| Hanging (walls) | 40-60 sheets/day (2-person crew) |
| Hanging (ceilings) | 30-40 sheets/day (2-person crew) |
| Taping (all coats) | 300-500 sq ft/day |
| Sanding | 500-800 sq ft/day |
Ceiling Note
Ceiling drywall is harder to hang and finish. Budget more time and consider using a lift for larger projects.
Cost Estimating
| Item | Typical Cost Range |
|---|---|
| 1/2" standard (4×8) | $10-15/sheet |
| 5/8" Type X (4×8) | $12-18/sheet |
| Joint compound (5 gal) | $15-25 |
| Tape (500 ft roll) | $5-8 |
| Screws (1 lb) | $8-12 |
Prices vary by region and market conditions