Drywall Calculator
Calculate 4x8 or 4x12 sheets needed for walls and ceilings. Includes estimates for mud, tape, and screws.
Room Measurements
Your Estimate
4x8 Sheets
0
drywall sheets
Area Breakdown
The Math Behind the Calculator
Drywall Sheet Formula
Sheets = Total Area / Sheet Size
4x8 sheet = 32 sq ft | 4x12 sheet = 48 sq ft
The calculation determines total wall area (perimeter x height) plus ceiling area if included, then divides by sheet size. We round up since you can't buy partial sheets.
Supplies Estimator
- Joint compound (mud): 0.05 gallons per sq ft (5-gallon bucket covers ~100 sheets)
- Paper tape: 1 roll per 12 sheets
- Drywall screws: 1 lb per 5 sheets (1-1/4" for walls, 1-5/8" for ceilings)
- Corner bead: Measure all outside corners in linear feet
Drywall Types: Choosing the Right Board
Standard (White Board)
General-purpose drywall for interior walls and ceilings in dry areas. Most affordable option.
Moisture-Resistant (Green Board)
For bathrooms, kitchens, and laundry rooms. NOT for direct water contact - use cement board behind tile.
Mold-Resistant (Purple Board)
Paperless face resists mold growth. Best for high-humidity areas. More expensive but worth it for basements.
Fire-Resistant (Type X)
Required between garage and living space. 5/8" thick provides 1-hour fire rating. Check local codes.
Common Drywall Thicknesses
| Thickness | Weight (4x8) | Best Use |
|---|---|---|
| 1/4" | 38 lbs | Curved walls, repairs |
| 3/8" | 45 lbs | Patches, double-layer |
| 1/2" | 54 lbs | Standard walls |
| 5/8" | 70 lbs | Ceilings, fire-rated walls |
Pro Installation Tips
Hang Ceilings First
Ceiling drywall overlaps wall drywall. This creates a stronger joint and makes taping easier.
Horizontal vs Vertical
Hang sheets horizontally on walls. This creates fewer joints and puts the tapered edges (easier to tape) at eye level.
Stagger Seams
Never align vertical seams between adjacent rows. Offset by at least 4 feet to prevent cracking.
Use a Lift for Ceilings
A 4x12 sheet weighs 90+ lbs. Rent a drywall lift (~$35/day) - it's worth every penny for ceiling work.
Frequently Asked Questions
Should I use 4x8 or 4x12 sheets?
4x12 sheets mean fewer seams (less taping) but are heavier and harder to maneuver. Use 4x12 for professionals or rooms with 8-foot ceilings where one sheet covers wall-to-wall.
How many coats of mud do I need?
Standard finish requires 3 coats: tape coat (embed tape), fill coat (build up), and finish coat (smooth and feather). Each coat should dry 24 hours before the next.
What's the difference between mud and spackle?
Spackle is for small repairs and dries quickly. Drywall mud (joint compound) is for taping seams - it's more flexible and sandable. Don't use spackle for seams.