WoodCalc
Board feet, miter angles, dovetail spacing, crown molding compound cuts, and wood shrinkage. No signup. No ads (yet). Works on your phone at the job site.
Board Foot Calculator
Calculate board feet from thickness, width, and length. Supports multiple boards and pricing.
Miter Angle Calculator
Find the miter angle for any number of sides. Regular polygons, picture frames, and custom joints.
Dovetail Spacing
Calculate pin and tail spacing for hand-cut dovetails. Even distribution with configurable ratios.
Crown Molding Angles
Miter and bevel angles for crown molding at any spring angle and corner angle. Inside and outside corners.
Wood Shrinkage
Estimate dimensional change from moisture content shifts. Tangential, radial, and longitudinal movement.
About WoodCalc
WoodCalc is a collection of free woodworking calculators designed for carpenters, furniture makers, and hobbyist woodworkers. Every tool runs entirely in your browser — no data is sent to any server, no account is required, and results are instant.
The board foot calculator helps you estimate lumber costs and quantities. The miter angle tool handles regular polygons and custom angles for picture frames, boxes, and trim work. Dovetail spacing calculates even pin-and-tail distribution for hand-cut joints. The crown molding calculator solves compound miter and bevel angles — the math most woodworkers dread. And the wood shrinkage estimator helps you plan for seasonal wood movement in your projects.
All calculations can be shared via URL — just copy the address bar after calculating to send your exact inputs and results to a colleague or save them for later.
Board feet calculation: board feet = (thickness in inches × width in inches × length in inches) / 144. A board 1 inch thick × 6 inches wide × 8 feet long = (1 × 6 × 96) / 144 = 4 board feet. Lumber under 1 inch thick is sold as if it were 1 inch (minimum thickness for board foot pricing). The nominal vs actual dimension confusion: a 2×4 actually measures 1.5 × 3.5 inches; dimensional lumber shrinks during drying and planing.
Wood movement: wood moves across the grain with humidity changes but is essentially stable along the grain. The tangential movement rate (flat-sawn) is roughly twice the radial movement rate (quarter-sawn). A flat-sawn oak board 12 inches wide with 4% moisture content change moves approximately 12 × 0.0086 × 4 = 0.41 inches (7/16"). Quarter-sawn lumber of the same species moves roughly half as much. This is why wide panels and table tops need room to move in their frames.
Finishing coverage: oil-based stains and penetrating oils typically cover 200–400 sq ft per gallon on smooth, closed-grain woods; 100–200 sq ft on open-grain or rough wood. Film finishes (polyurethane, lacquer) cover 400–600 sq ft per gallon per coat on smooth surfaces. Always apply multiple thin coats rather than one thick coat — thick coats trap solvents, dry unevenly, and produce a cloudy or crinkled finish.
Glue joint strength: a properly glued wood joint with good surface contact is stronger than the wood itself — the wood fibers fail before the glue line. Surface prep is critical: machine-planed surfaces with .003–.006 inch gap tolerance maximize glue contact. Clamping pressure should close any gaps and push out minimal squeeze-out (excessive squeeze-out wastes glue; none indicates surfaces didn't touch). PVA glue reaches 80% strength in 1 hour and full strength in 24 hours at room temperature.