Lumber & Wood Calculator
Board feet, sheets, decking, and studs. Choose US or metric, add waste and prices, and get cost and weight.
Overview
This page helps you plan a lumber purchase without spreadsheets or guesswork. Enter your sizes once, switch between US and metric, and see board feet, sheet counts, decking linear feet, and framing studs with plates. You can add waste, moisture, wood species, and prices to estimate both cost and weight. When you’re done, export a CSV for your order or job notes.
How to use
- Pick units: Choose US or metric in Settings. Hints and defaults change automatically.
- Board feet: Leave “Use nominal sizes” on to work with 2×4, 2×6, etc. Turn it off if you want to type actual thickness and width. Add rows for each size and length, then click Calculate.
- Plywood / sheets: Enter a single area or multiple rectangles. You can change sheet size and thickness for weight. Waste bumps coverage so you don’t come up short.
- Decking: Provide deck length and width, actual board face width, gap, and board length. The tool returns boards across and total linear feet including waste.
- Studs & plates: Set wall length, height, spacing (16″ or 24″ on center), extras for corners/openings, and whether you want a double top plate. Optional prices estimate material cost.
Interpreting results
The summary panel combines all volumes and weight using your selected species density and moisture factor. Costs roll up from any sections where you entered pricing. If you use both “price per board foot” and “price per piece” in Board Feet, the calculator picks the lower total to avoid double counting. Treat weight as an estimate; real-world moisture can vary widely.
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FAQ
What is a board foot?
One board foot equals a piece 1″ thick × 12″ wide × 12″ long. We compute board feet as (thickness in × width in × length ft) ÷ 12.
Why do my “nominal” sizes look smaller?
Nominal sizes (like 2×4) refer to rough-cut lumber before surfacing. The actual size of a 2×4 is typically 1.5″ × 3.5″.
How much waste should I add?
For framing, 5–10% is common. For finish work or complex layouts, 10–15% provides a safer buffer.
How accurate is the weight?
Weight uses species density and your moisture factor. Fresh or wet lumber can be much heavier; always lift and transport safely.
Can I export the numbers?
Yes. Each section includes a CSV export button so you can keep records or share with suppliers.