Woodworking Math Calculators

Which calculator do you need?

The four calculators on this page each solve a different problem. If you are not sure which one to open first, the table below maps common woodworking tasks to the right tool.

After calculating materials and cost, the next step is pricing your project for sale. See the woodworking pricing calculator which takes your material cost and adds labour, overhead, and channel fees.

Board feet calculator

Board feet is the standard volume unit for pricing and ordering hardwood lumber in North America. A single board foot equals 144 cubic inches — the equivalent of a piece 1 inch thick, 12 inches wide, and 12 inches long. Once you understand the unit, calculating your lumber order becomes straightforward arithmetic.

The board feet formula

Board feet = (thickness in inches × width in inches × length in inches) ÷ 144

For a board measuring 1″ thick × 6″ wide × 96″ long (that is, a 1×6 at 8 feet): (1 × 6 × 96) ÷ 144 = 4 board feet.

The board feet calculator handles multiple boards simultaneously, applies a waste factor automatically, and shows your total order quantity — so you arrive at the lumber yard with a precise shopping list rather than a guess.

Why waste factor matters

Rough-sawn hardwood always contains defects — knots, splits, bow, and wane along the edges. Surface-planing removes thickness. Cross-cutting removes ends. A standard waste allowance of 20% is appropriate for clear hardwood bought from a specialist dealer. Budget 25–30% for lower-grade lumber, heavily figured wood, or projects with very small parts where offcuts cannot be reused. Skipping the waste factor is the most common reason beginners run short of material mid-project.

Lumber for the project: Rockler stocks a wide range of hardwood species and will cut boards to rough length for you.

Lumber cost calculator

Knowing your board feet tells you how much wood to buy. The lumber cost calculator converts that quantity into a dollar figure, so you can budget accurately before you commit to a project or quote a price to a client.

Why lumber costs vary so much

Hardwood is priced by the board foot, and the range across species is wide. Poplar runs $3–$5/bf and is the standard choice for painted furniture. Hard maple runs $6–$9/bf and is worth the premium for tabletops, cutting boards, and anything taking heavy wear. Walnut and cherry sit at $10–$16/bf and above, making material cost the dominant variable in project pricing for furniture at that level. Exotic species (wenge, purpleheart, padauk) can exceed $20/bf and should always be budgeted precisely before ordering.

Dimensional softwood (pine 2×4s, 2×6s) is typically priced by the linear foot at home centres — the lumber cost calculator handles both pricing conventions.

Material cost feeds directly into project pricing

The number you get from the lumber cost calculator is your materials line in the project pricing formula. Feed it directly into the woodworking pricing calculator alongside your labour hours, overhead, and target margin to get a recommended selling price. Calculating material cost separately first makes the pricing step faster and more accurate — you are not guessing at a lump sum.

Compound miter angle calculator

A compound miter cut sets two angles simultaneously: the miter angle (the horizontal rotation of the saw fence) and the bevel angle (the tilt of the blade). Getting both right is essential for angled frames, shadow boxes, multi-sided boxes, and crown moulding. Getting either one wrong by even half a degree produces a gap at the joint that no amount of sanding will fix.

When you need compound angles

Simple mitre cuts — a 45° corner on a picture frame, for instance — require only a miter angle with the blade at 90°. Compound angles are needed when the workpiece is also tilted: a tapered box where the sides lean outward, an octagonal planter with sloped sides, or crown moulding that sits at a spring angle against the wall and ceiling simultaneously.

The trigonometry involved is not difficult, but it is not intuitive either. The compound miter calculator takes your work angle (the tilt of the finished piece) and the number of sides, and returns the exact miter and bevel settings to dial into your saw — with an explanation of what each angle means so you can verify the result makes sense before you cut.

Checking your settings before cutting

Always test compound miter settings on scrap before cutting your project wood. Even with calculated angles, small differences in saw calibration can introduce error. Cut four test pieces, dry-assemble the joint, and check for gaps before committing to final material. For large CNC-assisted projects, the woodworking design software guide covers tools like Fusion 360 that can model compound joinery digitally before any cuts are made.

Woodworking unit converter

Woodworking in 2026 means working across measurement systems constantly. Plans from European designers use millimetres. North American dimensional lumber is listed in inches and feet. Hardware — hinges, drawer slides, screws — is specified in mixed units depending on the manufacturer's country of origin. CNC and laser files may be set up in either system. The unit converter eliminates the mental arithmetic and the transcription errors that come with it.

Most common woodworking conversions

The conversions woodworkers reach for most often:

• Millimetres to fractional inches — the hardest conversion to do mentally, since fractions don't map cleanly to decimal millimetres. The converter returns the nearest standard fraction (¹⁄₁₆″ resolution) alongside the exact decimal.
• Board feet to cubic metres — needed when ordering from international suppliers or comparing prices across markets.
• Linear feet to metres — for converting plan dimensions when working from metric drawings.
• Inches to centimetres — the simplest conversion, but still faster as a lookup than mental arithmetic mid-project.

The converter also handles common lumber dimensions — so you can look up what a European 44×94mm section equates to in standard North American sizes, or confirm that an 18mm sheet of plywood is a true ¾″ equivalent (it is not — ¾″ = 19.05mm, and manufactured sheet goods are often undersized relative to their nominal thickness).

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