Finishing & Materials Calculators

Finishing and material choices are where a project gets its look, and where wood's natural behavior shows up. Wood moves with humidity, varies in hardness and weight, and takes stain differently. The tools here cover trim geometry, stain coverage, weight, hardness, cost and wood movement.

Which tool answers which question

Crown Molding Calculator: Estimate linear feet and stock pieces of crown molding needed for a room.
Lumber Cost Calculator: Calculate total lumber cost from board footage and price per board foot.
Miter Angle Calculator: Get the compound miter and bevel angles for crown molding at any corner angle.
Wood Movement Calculator: Estimate how much a board will expand or shrink across the grain with seasonal humidity changes.
Wood Species Hardness (Janka Scale): How common wood species compare on the Janka hardness scale, from softest to hardest.
Wood Stain Coverage Calculator: Calculate how much stain you need based on surface area and number of coats.
Wood Weight Calculator: Estimate the weight of lumber by species and board footage.

Trim and angles

Crown molding and miter cuts depend on the angle of the corner and, for crown, the angle at which it sits against the wall. Cutting a spare piece first is cheap insurance, because walls are rarely perfectly square.

Wood movement, hardness and weight

Wood swells and shrinks across the grain as humidity changes, far more than along it, and the movement tool estimates the change from the species, the width and the humidity swing. Hardness on the Janka scale shows how well a species resists denting and how hard it is to work. Weight depends on species and moisture, and matters for transport and for structures that carry it.

Stain and cost

Stain coverage depends on the wood, how porous it is, the number of coats and the product, and the label gives the coverage per gallon. Lumber costs vary widely by region, grade and season, so use your own supplier's prices.

Common mistakes

Ignoring wood movement. Leave room for boards to expand and contract.
Buying stain by the label alone. Test on a scrap of the same wood.
Assuming a species name means a grade. Check the stamp and the supplier.
Cutting trim without a test piece. Walls are rarely square.