Gypsum Board Calculator

Boards, screws, tape, and compound for walls, ceilings, and curved applications

Board Type

Sheet Size

Board Thickness

Board Layers

Double layer improves fire and acoustic ratings

Fixing Method

Stud Centres

Waste Allowance (%)

10%

10% for straightforward rooms; 15-20% for curved work or rooms with many openings.

Surfaces / Areas

Include Accessories

Drywall Screws

Based on fixing method & stud spacing

Jointing Tape

25 m rolls for all joints

Joint Compound

15 kg bags for taping & finishing

Corner Bead

Metal stop bead for external corners

Job Costing (optional)

Cost per board

Cost per 1,000 screws

Cost per tape roll (25 m)

Cost per compound bag (15 kg)

Cost per metre corner bead

Labour per m²

Results

Boards to Buy
-
boards

Total Net Area

m²

Area inc. Waste

m²

Surface Breakdown

Surface	Type	Gross Area	Deductions	Net Area	Boards (net)

Board Type Guide

Type	Best for
Standard (W)	General walls & ceilings, dry lining
MR (Green)	Kitchens, bathrooms, humid spaces
FR / Type X	Fire compartments, garages, commercial
Impact (I)	Corridors, schools, hospitals
Acoustic	Party walls, home cinema, studios
Flexible	Curves, arches, radius features

Thickness Guidance

Thickness	Typical use
6.5 mm	Flexible board for curves
9.5 mm	Ceilings, lightweight lining
12.5 mm	Standard walls & ceilings
15 mm	Enhanced fire & acoustic performance
18 mm	High-impact, substrate for tiles
25 mm	Composite insulated board

Screw & Accessory Guide

Stud fixing at 400 mm centres - approx 18 screws per m² per layer.
Stud fixing at 600 mm centres - approx 12 screws per m² per layer.
Dot-and-dab - typically 1 tub adhesive per 6-8 m²; screws not required.
Jointing tape - 25 m roll covers approx 12 m² of board.
Joint compound - a 15 kg bag typically covers 15-20 m² for taping coat + 2 finish coats.
Corner bead - measure total linear metres of external corners.

Gypsum Board Calculator