About this calculator

How-to: enter the wall/ceiling area, choose your sheet size and whether you're doing single or double layer (fire-rated / acoustic). We compute sheets = area ÷ sheet-area × waste factor (10% walls, 15% ceilings, 20% complex). Screws: 30/sheet walls, 40/sheet ceilings at 300 mm centres. Tape: 2.5 lm per m² of board. Joint compound: 0.4 kg per m² for tape-and-joint, 1.2 kg/m² for full skim.

Frequently asked questions

How much waste should I really allow?

10% for simple square rooms is realistic. For ceilings, sloped rooms, dormers and lots of penetrations, budget 15–20%. Half-sheets from cutouts can offset waste if the room is big.

When do I need 2 layers of board?

Fire compartmentation (EI60/EI90), party walls between dwellings, acoustic separation (Robust Detail E-WM-1), and stud walls over 4 m unbraced height.

What thickness board?

12.5 mm standard walls, 15 mm ceilings and fire-rated, 9.5 mm curved surfaces. In the US: 1/2" walls, 5/8" fire code / ceilings on 16" centres.

What does the Plasterboard / Drywall Sheet Optimizer do?

Sheet count, waste factor, screws, tape and joint compound for a wall or ceiling area — supports EU 1200×2400/2500/3000 mm and US 4×8/4×10/4×12 ft boards. How-to: enter the wall/ceiling area, choose your sheet size and whether you're doing single or double layer (fire-rated / acoustic). We compute sheets = area ÷ sheet-area × waste factor (10% walls, 15% ceilings, 20% complex). Screws: 30/sheet walls, 40/sheet ceilings at 300 mm centres. Tape: 2.5 lm per m² of board. Joint compound: 0.4 kg per m² for tape-and-joint, 1.2 kg/m² for full skim.

Is the Plasterboard / Drywall Sheet Optimizer free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the Plasterboard / Drywall Sheet Optimizer?

Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified plastering & drywall professional before committing to a purchase or a job.

What inputs does the Plasterboard / Drywall Sheet Optimizer need?

Enter values for: Total area (m²), Surface, Sheet size, Layers, Finish, Sheet price. Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the Plasterboard / Drywall Sheet Optimizer on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.