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Lumber Calculator

Fast, simple estimates for framing, boards & trim, and sheet goods — with waste & pricing. Imperial and metric.

Walls
Wall 1
Openings (doors & windows)

No openings — studs will not be deducted.

Framing estimate
26
total pieces
Regular studs
18
Jack studs
0
Cripple studs
0
Plate pieces
8
Board feet
100.10 BF
Est. offcut
4.0 ft
Cost (by piece)
$157.30

Estimates for planning only. Verify with your supplier before ordering.

How it works

Lumber Calculator – Fast, Accurate Material Estimates

Use this free lumber calculator to size materials for common projects. Whether you're framing a room, running skirting or fascia boards, or laying down sheets of plywood/OSB, this tool gives you quick piece counts, board feet (BF) or cubic meters (m³), estimated offcuts, and optional cost. It supports both metric and imperial units and uses real-world defaults with editable waste.

Nominal vs actual

You pick the nominal size (e.g., 2×4 or 90×45). The calculator uses the actual finished dimensions to compute volume precisely.

Board feet / m³

Imperial projects use board feet (BF), calculated from thickness × width × length ÷ 12. Metric projects use cubic meters (m³).

Waste allowance

Add 5–15% to cover trim cuts, knots/defects, and handling losses. You control the percentage — 10% is a safe default.

Framing Lumber: Studs & Plates

For stud walls, counts are driven by wall length, stud spacing (e.g., 400 mm / 16 in), and wall height. Corner studs and simple opening rules are included, plus single or double top plates. You'll see the number of studs, plate pieces by stock length, and overall volume for ordering.

Boards & Trim: From Linear Run to Pieces

Enter a total linear run and select the sizes and stock lengths you plan to purchase. The tool converts to pieces, estimates offcuts, and reports board feet/m³. Ideal for skirting, fascia, picture rails, handrails, and general trim.

Sheet Goods: Plywood & OSB

Provide the area length and width and pick a standard sheet size (e.g., 1220×2440 mm or 4×8 ft). The calculator returns sheet counts and total coverage with your waste allowance — perfect for floors, walls, and roofs.

Board feet (BF) = Thickness(in) × Width(in) × Length(ft) ÷ 12
Studs = ⌈Wall length ÷ spacing⌉ + 1 + 2 corner studs
Sheets = ⌈(Area × waste factor) ÷ sheet area⌉
FAQ

Frequently asked questions

Accuracy & Review

Reviewed by: Liam Santos. Liam reviews our decking, lumber, and board foot calculators to confirm accurate framing takeoffs, dimensional lumber calculations, and waste assumptions. He focuses on ensuring estimates reflect practical framing layouts and real-world material usage.

Last updated: Feb 12, 2026

Important disclaimer: These estimates are for general planning purposes only and should not be used as structural design guidance. Actual lumber quantities depend on span limits, load requirements, material grade, and building code compliance. Structural framing components should be verified against current code requirements before construction.

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Roof pitch, stair calculator, drywall, paint coverage, and more are next.

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