Drywall Calculator
How to Calculate How Many Drywall Sheets You Need
Drywall (also called plasterboard or gypsum board) is the most common wall finishing material. Getting the right quantity avoids waste and extra trips to the store. Once your drywall is installed and taped, head over to our paint calculator to work out how much paint you need for the finished walls.
The Drywall Calculation Formula
Sheets needed = Wall Area ÷ Sheet Area (rounded up)
Standard sheet: 1200mm × 2400mm = 2.88 m² per sheet.
Step-by-Step Guide
- Measure wall dimensions — Record the total length and height of all walls to be covered.
- Calculate total area — Length × Height for each wall, then sum them.
- Divide by sheet area — Standard sheet covers 2.88 m².
- Round up — Always round up to whole sheets. Drywall can't be spliced.
Materials List for Drywall Installation
| Material | Quantity per m² | Purpose |
|---|---|---|
| Drywall Screws | 8-10 pcs | Fastening to studs |
| Joint Tape | 1.2 m (tape length = joint length) | Reinforcing joints |
| Joint Compound | 1.5 kg | Covering joints and screws |
| Corner Bead | As needed | Protecting outside corners |
Drywall Thickness Guide
| Thickness | Use Case |
|---|---|
| 9.5mm | Ceilings, curved walls, repairs |
| 12.5mm | Standard walls (most common) |
| 15mm | Fire-rated walls, soundproofing |
| Double layer | Maximum fire/sound rating |
Tips for Accurate Estimates
- Subtract large openings only if they're bigger than one sheet
- Order 5-10% extra for cuts and waste
- Plan your layout to minimize joints and waste
- Consider sheet orientation — horizontal installation is standard for walls
- Insulating first? If you are fitting insulation behind the drywall, measure and install it before closing up the wall
Drywall Types Beyond Standard Plasterboard
"Drywall" covers several specialised boards. Picking the right one matters more than picking the right brand:
| Type | Colour Code | Best Use | Premium vs Standard |
|---|---|---|---|
| Standard plasterboard | Ivory / white | Bedrooms, living rooms, most ceilings | — |
| Moisture-resistant (MR / "green board") | Green | Bathrooms, kitchens, utility rooms | +20-30% |
| Fire-resistant (Type X / "pink board") | Pink | Garages, kitchens with cookers, party walls | +30-50% |
| Acoustic / soundproof | Blue or marked | Bedroom party walls, home cinemas | +60-100% |
| Impact-resistant | Yellow / branded | Hallways, kids' rooms, rentals | +40-60% |
| Cement / tile backer | Grey | Behind floor and wall tiles in showers | +80-120% |
| High-flex (curved) | Standard or marked | Curved walls, vaulted ceilings | +50-80% |
Most building regs across Europe require fire-rated board on garage ceilings, between flats, and in escape routes. Don't skip it.
Sanding and Finishing Levels
Drywall finish quality is graded Level 1-5 and determines how the wall reads under light. Quote requests should specify the level — it's a major cost driver:
| Level | Description | When Used | Time Multiplier |
|---|---|---|---|
| Level 1 | Tape over joints only | Above ceilings, service areas | 1.0× |
| Level 2 | Tape + skim coat over joints/screws | Garages, behind tile | 1.3× |
| Level 3 | Two coats over joints/screws | Heavy texture / wallpaper | 1.6× |
| Level 4 | Three coats, sanded smooth | Standard painted walls | 2.0× |
| Level 5 | Skim coat over the entire surface | Glossy paint, raking light | 3.0× |
Level 5 is the only finish that hides every joint under a glossy or low-sheen paint in raking sunlight; Level 4 is the practical default elsewhere.
Materials Cost for a Typical Room
Approximate costs for fitting out a 4×4 m room with 2.4 m ceilings (~38 m² of wall plus 16 m² of ceiling, total ~54 m²):
| Material | Quantity | Approx Cost (EUR) |
|---|---|---|
| 12.5 mm plasterboard sheets | 19 sheets | 190-285 |
| Drywall screws (5 kg) | ~500 screws | 12-18 |
| Joint tape (paper, 75 m roll) | 1 roll | 4-7 |
| All-purpose joint compound (20 kg) | 4 buckets | 80-120 |
| Corner bead (2.4 m lengths) | 4-6 | 12-25 |
| Sandpaper / mesh (assorted grits) | Pack | 10-15 |
| Total materials | — | 310-470 |
Add 50-70 hours of skilled labour for a Level 4 finish at €30-50/hour, putting full installed cost around €1,800-3,800 per room.
Common Mistakes to Avoid
- Wrong screw spacing — 200 mm on edges, 300 mm in the field. Wider spacing causes "popping" as the building moves.
- Skipping corner bead — External corners crack within months without bead reinforcement.
- Filling joints in one thick coat — Compound shrinks and cracks. Three thin coats is the rule.
- Sanding before the compound is dry — Tears the surface and fills the air with gypsum dust. Wait 24 hours per coat.
- Using paper tape on internal corners without folding it correctly — leaves a hairline crack that telegraphs through paint.
- Insulating first? If you are fitting insulation behind the drywall, measure and install it before closing up the wall.
When to Hire a Professional
Drywall finishing (mudding and taping) is one of the most skill-intensive renovation tasks. Consider a professional for visible areas, ceiling work, or any Level 4-5 finish quality. If the bottom section of the wall will be tiled instead of painted, use our tile calculator to get the right tile count.
These calculations are estimates only. Actual requirements may vary depending on surface conditions, product specifications, and installation methods. Always consult a qualified professional for precise measurements.
Prices updated: 2026-03Frequently Asked Questions
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