What's different about these calculators
- 1. The knobs that actually matter. Generic board-foot calculators ignore defect allowance, planer waste, and rip kerf. Ours include all three — plus effective $/BF, the apples-to-apples comparison metric.
- 2. Code-aware results. Joist spans, stair stringers, and shear-wall nailing reference the actual IRC tables, not a one-line formula.
- 3. Practical limitations, stated up front. Each tool ends with an honest Limitations section — what it doesn't model, what species-dependent behavior you should still verify in the shop.
- 4. No signup, no tracking, no nonsense. Every calculation runs in your browser. Nothing is logged.
Lumber & Material
Board Foot Calculator with Waste & Defect Allowance
Estimate board feet for hardwood, softwood, or project packs — including realistic waste, defect, and planing allowances.
Plywood Sheet Cut Layout Optimizer
Plan the cuts on a 4×8 sheet, minimize waste, and see how many sheets you actually need for a cabinet or bookcase job.
Lumber Cost Estimator with Waste & Surfacing
Quote a project from a lumber yard price per board foot — accounting for defect, planing waste, and rip kerf.
Linear Feet ↔ Board Feet Converter
Translate between running feet of a known cross-section and board feet — useful for trim, decking, and 2× lumber.
Log Volume Calculator (Doyle / Scribner / International)
Estimate log board-foot volume using three scaling rules — and see how Doyle famously under-counts small logs.
Cord of Firewood Calculator
Convert stacked volume to face cord, full cord, cubic feet, and approximate weight — by species.
Board Feet to Weight Converter
Convert board feet to pounds — by species, moisture content, and surfacing.
Hardwood Grade Yield Estimator
Estimate how many usable board feet you'll get from a FAS, No. 1 Common, or Select pack — by species and width.
Joinery
Pocket Hole Spacing & Screw Selector
Pick the right Kreg-style pocket hole spacing for face frames, cabinet carcases, and edge-to-face joinery — with screw length by material thickness.
Mortise & Tenon Dimension Calculator
Size mortise width, tenon thickness, and shoulder length to your stock — with a rule-of-thumb that avoids weak joints.
Dowel Joint Spacing & Quantity Calculator
Plan dowel diameter, count, and spacing for edge-to-edge or edge-to-face joints.
Biscuit Joint Quantity Calculator
Figure out how many #0, #10, or #20 biscuits you need for a glue-up — by joint length and biscuit spacing rules.
Wood Screw Pull-out & Shear Estimator
Estimate withdrawal load and shear capacity for a wood screw by species, diameter, and embedment depth.
Shear Wall Nail Pattern Calculator
Plan nail spacing and edge distance for a plywood/OSB shear wall — by panel grade, nail size, and seismic/wind zone.
Finishing
Wood Stain Coverage Calculator with Coat Count
Estimate how many quarts/gallons of stain you need — by surface area, coats, wood porosity, and waste.
Polyurethane / Varnish Coverage Calculator
Calculate how much poly, varnish, or hardwax oil you need — by surface area, coats, and product type.
Sandpaper Grit Progression Selector
Pick the right grits for your sanding job — from rough stock removal to final finishing — and don't waste steps.
Pre-Stain Wood Conditioner Coverage
Estimate conditioner needs for blotch-prone woods — pine, cherry, birch, maple — before stain or dye.
Workshop
Dust Collector CFM & Duct Sizer
Size a single-stage or two-stage dust collector for your shop — by tool count, duct length, and number of machines running at once.
Workshop Air Exchange Calculator
Estimate CFM of fresh-air ventilation needed for your shop, plus recommended filter change schedule.
Saw Blade Kerf & Material Waste Calculator
Quantify the wood lost to kerf across many cuts, and compare a thin-kerf vs full-kerf blade.
Planer / Jointer Snipe Loss Calculator
Estimate the length of usable board lost to snipe at the ends — and see if your technique or machine setup is costing you.
Design / Structural
Shelf Sag & Load Capacity Calculator
Predict how much a shelf will sag under a distributed load — and the maximum load before the shelf looks unhappy.
Floor Joist Span Calculator
Check allowable spans for floor joists by species, grade, spacing, and deflection limit.
Rafter Length & Birdsmouth Calculator
Compute common rafter length, birdsmouth plumb and seat cuts, and overhang — from rise/run and pitch.
Stair Stringer Calculator (Rise / Run / Code Check)
Plan a stair stringer: rise, run, number of treads, headroom, and IRC code check.
Compound Miter & Bevel Angle Calculator
Get the miter and bevel angles for a compound cut — crown molding, picture framing, sloped soffits.
Project Planning
Offcut Reuse Planner
Tell it your parts and your scrap pile, and find which offcuts can become a new project — no extra lumber needed.
Wood Acclimation Timeline Estimator
Estimate how long your lumber should sit in the shop before milling — based on species, board thickness, and moisture differential.
DIY vs Buy-it Cost Calculator
Decide whether to make it yourself or buy it — by your hourly rate, materials, and tool amortization.
Time vs Material Tradeoff Calculator
Should you spend an extra hour planing to save a board, or just buy another board? Quantify the trade.
Wood Movement Calculator (Seasonal)
Predict how much a solid wood panel will expand or contract across seasons — across the grain, not along it.
How to pick a tool
Start with your job, not the math. Estimating a lumber order? Use the Board Foot Calculator and the Lumber Cost Estimator together. Planning a cabinet carcase? Plywood Cut Optimizer and Pocket Hole Spacing. Framing a shed? Joist Span, Rafter Length, and Stair Stringer. Finishing a tabletop? Sandpaper Grit Selector, Wood Conditioner, Stain Coverage, Poly Coverage. Each tool page tells you what it does, who it's for, and what it doesn't model.