Material Quantity Calculator
Wall/roof/floor area × (1 + waste factor) ÷ sheet area → sheet count + nail/screw estimate.
Result
Enter material and area.
What this tool does
The material quantity calculator determines sheets (or bundles/batts) required, waste-adjusted area, total weight, and fastener count for 11 common timber-frame materials: OSB (11 mm, 18 mm), plywood (12 mm, 18 mm), gypsum board (9.5 mm, 12.5 mm), cement board, fiber-cement siding, vinyl siding, asphalt shingles, and R-19 glass-wool batt insulation. Standard sheet sizes shipped in the Korean market are built in (1,220×2,440 mm for OSB/plywood; 900×1,800 mm for gypsum/cement board), and fastener estimates follow IRC R602.3 nail-spacing rules.
Who uses this
- Roof sheathing: compute OSB sheet count plus nail quantity for structural deck
- Interior finish: calculate gypsum-board sheets and screw count for walls and ceilings
- Exterior cladding: determine fiber-cement or vinyl siding linear pieces for façade
- Roofing: find asphalt shingle bundle count from actual roof area
- Insulation: count R-19 glass-wool batts for 2×6 stud wall cavities
How to Use (4 Steps)
- 1Select the material type: structural (OSB, plywood), interior finish (gypsum board), exterior cladding (cement board, siding), roofing (shingles), or insulation (glass-wool batt).
- 2Enter the installation area in m². For walls, multiply width × height × number of faces. For roofs, enter the actual sloped area — use the Roof Area Calculator first if you only know the plan footprint.
- 3Adjust the waste factor (default 10%). Simple rectangles: 5–10%; many cut-outs or diagonal patterns: 15–20%.
- 4Click Calculate to see sheet count (ceiling-rounded), adjusted area, total weight, and fastener count (nail or screw) based on standard edge/field spacing.
Formulas & Standards
Adjusted area = installation area × (1 + waste%/100) Sheets required = ceil(adjusted area ÷ area per sheet) Total weight = sheets × weight per sheet (kg) Built-in sheet sizes (Korean market standard): OSB / Plywood: 1,220 × 2,440 mm = 2.9768 m²/sheet (19–33 kg) Gypsum board: 900 × 1,800 mm = 1.62 m²/sheet (12–16 kg) Cement board: 900 × 1,800 mm = 1.62 m²/sheet (22 kg) Fiber-cement siding: 200 × 3,600 mm = 0.72 m²/piece (9 kg) Vinyl siding: 250 × 3,700 mm = 0.93 m²/piece (4 kg) Asphalt shingle: 1 bundle = 3.1 m² (33 sq. ft., 27 kg) Glass-wool R-19 batt: 600 × 2,400 mm = 1.44 m²/batt (5 kg) Fastener spacing (IRC R602.3): Structural sheathing (OSB/plywood): edge 150 mm OC / field 300 mm OC → nails Gypsum board: edge 200 mm OC / field 300 mm OC → screws
Examples
Example 1: OSB 11 mm roof sheathing, 80 m² area, 10% waste
Adjusted area = 80 × 1.10 = 88 m². Sheets = ceil(88 ÷ 2.9768) = ceil(29.6) = 30 sheets. Total weight = 30 × 19 kg = 570 kg. Nails estimated from perimeter ÷ 150 mm + interior rows × (2,440 ÷ 300). Plan a 570 kg cargo delivery.
Example 2: Gypsum board 12.5 mm, 45 m² walls, 15% waste
Adjusted area = 45 × 1.15 = 51.75 m². Sheets = ceil(51.75 ÷ 1.62) = 32 sheets. Weight = 32 × 16 = 512 kg. Screws estimated from edge 200 mm + field 300 mm spacing per sheet.
Example 3: Asphalt shingles, actual roof area 120 m², 12% waste
Adjusted area = 120 × 1.12 = 134.4 m². Bundles = ceil(134.4 ÷ 3.1) = 44 bundles. Weight = 44 × 27 = 1,188 kg. Shingles are excluded from fastener estimation — refer to manufacturer's nailing schedule.
Frequently asked questions
What is the difference between OSB and plywood?
OSB (Oriented Strand Board) is manufactured by compressing wood strands in alternating directions under heat and adhesive. Plywood uses thin veneer layers cross-laminated with adhesive. OSB is typically less expensive with uniform structural strength; plywood has a smoother face, slightly better moisture edge resistance, and is preferred for finish applications. Both are standard for roof and wall sheathing in timber-frame construction.
Why is one asphalt shingle bundle equal to 3.1 m²?
In US roofing convention, 1 'square' covers 100 sq. ft. (9.29 m²) of roof. Most shingle products use 3 bundles per square, so 1 bundle = 33.3 sq. ft. ≈ 3.1 m². Coverage accounts for the overlap (exposure) required between shingle courses. This calculator uses 3.1 m²/bundle as the built-in coverage constant.
What wall type is R-19 glass-wool batt designed for?
R-19 (thermal resistance roughly 3.35 m²·K/W) is sized for 2×6 stud wall cavities (140 mm deep). For 2×4 walls (89 mm cavity), R-11 or R-13 batts are the typical match. Korean energy regulations (Building Energy-Saving Design Standards) specify minimum U-values by climate zone — verify the required insulation thickness separately with those tables.
How should I set the waste factor?
Simple rectangular wall or roof panels: 10% is a reasonable default for the standard 1,220×2,440 mm sheet format. Many windows/doors or non-rectangular shapes: 15–20%. Diagonal siding patterns or multi-faceted roofs: up to 25%. Over-ordering raises cost, so refine the factor as you gain on-site experience with a particular material.
Why does total weight matter for ordering?
Weight determines vehicle payload (1-tonne pickup vs. 5-tonne flatbed), hoist or crane capacity for multi-story lifting, and temporary floor loading on scaffolding. Gypsum board and cement board (16–22 kg per sheet) are particularly heavy and typically require two workers per sheet plus plan for upper-floor deliveries.
Fiber-cement siding vs. vinyl siding — which should I choose?
Fiber-cement is durable (20–30+ year lifespan), fire-resistant, and paintable, but heavier (9 kg per piece) and labor-intensive to install. Vinyl siding is lightweight (4 kg), low-cost, and easy to install, but has lower fire resistance and can distort under extreme heat. In Korea's climate with wide seasonal temperature swings, allow adequate expansion joints in vinyl siding to prevent buckling.
Cautions
- •Sheet count is the minimum order quantity after rounding up. Add buffer for site-specific complexity beyond the stated waste factor.
- •Fastener estimates use IRC R602.3 standard spacing. Seismic or high-wind zones may require closer nail schedules or structural clips — check local requirements.
- •Asphalt shingles, vinyl siding, fiber-cement siding, and glass-wool batts are excluded from fastener estimation. Follow the manufacturer's installation instructions for nailing patterns.
- •Weight values are dry-condition references. Use code-prescribed unit weights (Korean Building Structural Standard KBC) for structural load calculations — do not use the tool weights for that purpose.
- •Gypsum board thickness selection for fire-rated assemblies (e.g., 9.5 mm vs. 12.5 mm for 30-minute or 60-minute ratings) depends on the fire-resistance design. Confirm with your architect.
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Last reviewed: 2026-06-17