Your cut list in. The boards to actually buy, and what one piece cost, out.
A board foot is the answer, not the question. Start from the parts of the thing you are building and this works out the lumber to buy — both waste factors named, the glue-up counted, the kerf counted, and whole boards, because two boards of walnut often make three cutting boards rather than two. Then one piece’s true cost, and the one thing board feet can never tell you on their own: whether the boards on your rack are long enough. Everything stays in your browser.
The piece
Pick what you are building and it fills in a starting size and a starting cut list from our own worked examples; change either and it stays yours. Thickness is in quarters, because that is what the yard bills — 4/4 is a nominal inch even after the mill surfaces it to 13/16″.
The cut list
One line per part: what it is, the species, the thickness you buy it in, and the finished size and count. The species matters — it is what finds your own product on the rack further down, and it is what decides the defect waste.
The boards to buy
The second gear. Every number here is yours, and the two waste factors are separate on purpose: one belongs to the species you buy, one to the job you are doing, and they multiply.
Will it fit
The question board feet cannot answer. Eighteen board feet of walnut is ten coat racks or none at all depending on how long the boards are — and a rack of short offcuts is the normal state of a hobby shop, because offcuts are what accumulate. One number closes most of it.
What one piece really cost
Lumber, glue, finish, abrasives and hardware. Your hours sit on their own line, because owner’s time prices the work — it is never a materials figure and never a tax number.
The finish
The one box on this page with no defaults at all, and the reason is in the answer.
The next fair
A finished piece is sellable the minute it is out of clamps — this is not a cure. What it has instead is two spans end to end: your build, and your own finish schedule. Signed in on this device, this reads your own show dates and works backwards through both.
Your rack
How many you can actually build from the lumber, glue, finish and abrasives on hand — and what is missing for the rest.
madekeeper.com/board-foot-calculator — sources checked September 5, 2026
What this page will not do, and why. It never computes a span, a load or a deflection. The only real tool in that space says outright that it is an appearance criterion built on “average wood stiffness properties of clear, straight-grained samples measured in controlled laboratory conditions,” with no factor of safety and a caveat that shelves sag a further 50% over time — and the failure mode of a wrong number is a loaded bookcase coming down, or a child falling out of a loft bed. Neither the actual grade of your board, nor the knots in it, nor your fasteners, nor the wall you anchored to is something we can see. So there is no shelf span here, no load rating, and no crib, bunk bed or loft bed in the list above.
It also never says a finish is food safe, and it will not help you say it. The FDA’s own food-contact rule for drying oils is decided by laboratory extraction — chloroform-soluble extractives measured off your actual cured film, weighed to a tenth of a milligram — so no arithmetic on a materials list can reach that conclusion, and the cure state is part of the definition of the thing being regulated. What we do instead is keep and print the finish you named, on the piece, with the date. Name the oil; never certify the property.
And it states no lead number, no small-batch dollar threshold and no certificate. If you sell to children the useful and mostly reassuring fact is that solid wood you have not coated is on CPSC’s own determination list — 16 CFR §1251.2 defines it as wood with “no added surface coatings (such as, varnish, paint, shellac, or polyurethane) and no materials added to the wood substrate”, and expressly excludes plywood, particle board, MDF and fiberboard — while the varnish, the stain, the paint and the hardware are not on it, and neither is reclaimed pallet wood, which 16 CFR Part 1252 treats as post-consumer waste. The small-batch registration relieves third-party testing only, never the limits or the tracking label, and its revenue threshold is indexed to inflation every year, which is exactly why we will not print it. One more that almost nobody knows: 16 CFR Part 1303 bans lead-containing paint on furniture for consumer use — “beds, bookcases, chairs, chests, tables, dressers, desks” — and that has nothing to do with children at all.
Fee rates as of July 29, 2026: Square in-person 2.6% + 15¢ (Square’s published pricing); Etsy $0.20 listing + 6.5% transaction + 3% + $0.25 US payment processing (Etsy’s Fees & Payments Policy). Simplified honestly: Etsy’s transaction and processing fees also apply to shipping you charge, and Offsite Ads (12–15% when they bring the sale) aren’t included. Booth uses Square’s free-plan card-present rate; a booth or table fee is its own cost — this page prices the piece, and the fair profit calculator prices the day.
The numbers here are yours to check. This page does arithmetic on what you type — it cannot see your recipe, your equipment or your batch.
This is one calculator, not six.
The form fills in the size and the cut list. The cut list gives the board feet, and the board feet plus your two waste factors give the lumber to buy — then the board width decides the glue-up, the kerf decides the strips, and whole boards decide how many pieces the invoice actually covers. All of it lands in what one piece cost, and the finished surface sizes the finish. Change the species, or the board width, and everything below rolls.
In your shop it is the same calculator with your rack behind it. Your lumber answers before you cut: “you can make 6 End-grain cutting boards with what is on the rack — the Hard maple 8/4 runs out first; a seventh would need 2 bf more,” with the numbers, and it keeps the lumber line and the abrasives line apart, because one is a drive to the yard with a minimum order on it and the other is the hardware store on the way home. Your next shows come off your own calendar and the build plus your finish schedule gets worked backwards for you. The plan lands in Make with How many already filled in and the lumber helper open on your own parts and your own waste factors. And the lumber becomes a real cost on a real piece, so your margin, your reports and your tax packet stop being computed without the biggest line on the bench. A web calculator cannot do any of that, because it has never seen your rack. $19/mo for the whole back office, kept for as long as you stay. The shop stays free for cost a piece and one fair — no product cap. The tax packet, Etsy and Square, and more fairs are the $19.
The lumber math, with the contested numbers named
Everything on this page is arithmetic on numbers you own — inches, board feet, a kerf, a price your dealer published. Where the trade genuinely disagrees, the setting is yours and the answer says which figure it used.
What is a board foot, exactly?
A volume, not a length: one board foot is a piece 1 inch thick, 12 inches wide and 12 inches long — thickness × width × length in inches, divided by 144. It exists because hardwood comes in random widths and lengths, so the yard prices the wood itself rather than the stick. An 8-foot 4/4 board 6 inches wide is 4 board feet regardless of which tree it came off.
Why enter nominal thickness when my board measures 13/16″?
Because the invoice does, and the standard says so. PS 20-25 §2.2, the American Softwood Lumber Standard, defines board measure using “the nominal thickness in inches or fraction of an inch by the nominal width in feet by the length in feet” — and §2.5 draws the contrast deliberately, reserving the dressed size for cubic measure. NHLA Rule 14 generates the surfaced chart by “subtracting 3/16″ from standard rough thickness for lumber 1-1/2″ thick or less”, which is where 13/16″ comes from, and USDA FPL Wood Handbook Table 6-4 reproduces it identically. That is why thickness on this page is a picker of quarters rather than a free-text box: there is nothing left to get wrong, and the milling gap between what you buy and what you finish becomes a number the page can show you instead of one it silently absorbs.
“4/4” keeps arriving at different thicknesses. Which is right?
All of them, which is why the surfaced figure is a fit check here and never touches the price. NHLA, USDA FPL, Woodworkers Source and Ocooch all say 13/16″ for a surfaced 4/4 board. Bell Forest publishes 15/16″ across its whole catalogue. AHEC’s official illustrated guide allows a scant tolerance on top: “Rough kiln dried lumber specified 3/8″ to 1 3/4″ thick may be 1/16″ scant of the nominal thickness.” And Ocooch sells 4/4 as three separate lines — 3/4″, 13/16″ and rough. So “4/4” tells you what you will be billed for, which is the inch, and very little about what turns up on the truck.
How much waste should I plan for?
Two numbers, not one, and they multiply — which is the finding that changed this page. The defect loss belongs to the species and grade: Hearne Hardwoods publishes “Mahogany, Sapele, Spanish Cedar … Clear Grades – Add 20% / Red Oak, White Oak, Poplar, Ash, Birch, Pine, Maple – Add 25% / Cherry – Add 35% – 75% … Walnut & Butternut – Add 50% – 100%”. The process loss belongs to the job: The Knotty Lumber Co.’s own calculator offers “Tables 20% · Cutting boards 50% · Charcuterie 10% · Millwork 30%”. A single shop-wide percentage cannot be right for both, and no standards body publishes a project waste figure at all. Underneath both sits a real floor you can look up: FAS guarantees only 83-1/3% clear face, No. 1 Common 66-2/3% and No. 2A Common 50% (USDA FPL Table 6-1), which is also the argument for buying a lower grade when your parts are small.
Is “20% waste” the same as “buy 20% more”?
No, and the difference is about a third. Buying 20% more than a 100 board foot cut list is 120 board feet; a true 20% waste rate needs 100 ÷ 0.8 = 125. Both phrasings are in circulation from people who know what they are doing — a woodworker on WOODWEB spells it out (“If you have 30% waste then you need to purchase 142.85 board feet to get net 100 feet”) and the person who asked concedes he was “just adding on 30% more lumber… which is actually 23% waste”. This page adds the factors on top of the cut list, so it is the “buy more” version, and it prints the yield percentage beside it so you can see which one you are looking at.
Does the blade kerf really change anything?
It changes whole strips. Nine 1¼″ strips out of a 12″ board need 11¼″ of wood plus eight kerfs: at a full 0.125″ that is 12.002″ and they do not fit, and at a thin 3/32″ it is exactly 12.000″ and they do. The published spread on a 10″ blade is wider than the folklore — Forrest’s Woodworker II is “.125″ (3.2mm)” and its Ultra Thin Kerf “.080″”, Freud’s full kerf is .126″ and its thin .090″, and Diablo’s commonest 10″ blades are .098″. On an end-grain board it compounds, because Old Line Woodcraft’s published arithmetic is “segments × crosscut width, plus one kerf between each pair of segments” — thirteen crosscuts turn an inch and a half of finished board into dust.
Why does buying two boards sometimes make three pieces?
Because you buy whole boards, and nobody’s calculator says so. If a cutting board wants 2.5 board feet of walnut and the rack holds 8-foot 4/4 boards 6 inches wide, each board is 4 board feet — so two boards is 8 board feet, which covers three cutting boards, not two. The third one’s lumber is already paid for and the third one is nearly pure margin. This page says it when it is true and stays quiet when it is not: on a tray that eats a whole board there is no free step at all, and pretending otherwise would be worse than silence.
Can board feet tell me whether I have enough lumber?
No, and this is the honest limit of every inventory number in this trade, ours included. Board feet is a fungible unit for a material that is not fungible. Eighteen board feet of walnut held as eleven 43″ boards makes ten coat racks; the same eighteen board feet held as twenty-four 20″ offcuts makes none; six 79″ boards makes ten again. Same number on the shelf, three different truths, and the catastrophic case is the normal state of a hobby shop, because offcuts are what accumulate. Rather than pretend, this page asks the one thing you can answer without leaving the sofa — how long is the longest board on your rack — and until you answer it, every quantity is labelled a ceiling.
Will you tell me what a cutting board should sell for?
No. The pricing conventions in circulation do not survive being checked: The Wood Whisperer rejects them outright — “no, taking 2X or 3X the material cost is not good enough. Wood can vary in price from $1/bf to $50/bf” — SoloWoodworker gives ×5 and ×8, and “materials × 3” could not be sourced to any readable page at all. There is no per-square-inch rule either; the ones you see quoted are arithmetic somebody did on a retailer’s price list. What we do instead is the back-solve, which is the useful and slightly brutal part: your price divided by your hours is what this piece paid your hands an hour.
Will it tell me if my shelf will hold, or if my finish is food safe?
No to both, and those refusals are load-bearing. A span number’s failure mode is a bookcase coming down and we cannot see the grade of your board, the knots in it, your fasteners or your wall. A food-safety claim’s failure mode is a false statement on an object somebody eats off — and the FDA’s own rule for drying oils is settled by laboratory extraction from your actual cured film, not by anything on a materials list. Note what the finish makers themselves do: General Finishes renamed “Salad Bowl Finish” to “Wood Bowl Finish” and conditions it on a 30-day cure. So we record and print the finish you named, with the date, and we never compose the claim.