About Carpentry Hub
Carpentry Hub (wendingzy.com) is a small set of free tools that turn "work it out by hand again, then go looking it up again" into "fill in a few boxes, press one button". The site currently holds 32 tools. The site is about: Carpentry Hub. Everything runs in your browser: no sign-up, no login, nothing you type is uploaded.
Who it is for
Three groups, mostly. First, people who already have the numbers and simply do not want to re-key them into a calculator every time - someone drafting a budget, or an operator who needs a rough figure to align with a colleague in the next ten minutes. Second, people preparing for an exam, an interview, an application, or a document they have to submit, who want a way to test "what if I change this number". Third, teachers, coaches, and leads who need to explain a rule of thumb rather than hand over an answer.
Whatever group you are in, the position of this site is the same: it puts the reasoning in front of you instead of making the decision for you.What a tool returns is a reference value computed from the inputs you supplied. Before you act on it, you still check it against the source material, the situation on the ground, or the official guidance.
How the tools are built
Every tool has an explicit, reproducible method: what goes in, what formula is applied, what comes out. The logic is not hidden - the full calculation is visible in the page source. That buys two things. The result can be checked by somebody else, and if you think a number is wrong you can follow the formula to the step whose assumption does not hold, instead of choosing between trusting it and not trusting it.
Because all of it runs locally, the amounts, durations and ratios you type never leave the device. That matters most for the inputs that describe your own situation.
How the content is held to a standard
Every page has a floor it has to clear: enough body copy that it is not just a form with a button; at least four questions answered, with the three things that actually decide whether a tool is used well written down - how to use it, where people go wrong, and when it does not apply. Where a page states a specific number, a price, a fee or a rule, it says "check the official source" and gives you a route to check it yourself, rather than inventing a number that looks plausible.
Instructions, the verdict labels and the computed result are kept separate. Instructions tell you how to use the tool, the labels qualify what the number means, and the result is the number. Mixing those three is how a conclusion drawn under one set of conditions quietly turns into a general rule, and it is a mistake we keep going back and fixing.
What this site does not do
It does not give medical diagnoses, medication doses, legal opinions or investment advice. The tools help you frame a question better or get the arithmetic right; the conclusion still comes from a qualified professional or from the official source. For outdoor, diving, wildlife, protected-area and border situations, the site provides safety checklists and official contacts only - it does not provide decompression tables, does not certify any depth or weather as safe, and does not explain how to work around regulations.
What changes over time
Tool pages get reviewed: does the logic still hold, is the reference data still current, are the stated limits still true. When the premises of a tool change, the wording on the page changes too, rather than leaving a stale conclusion in place. If a page does not match what you are seeing in practice, the contact details in the footer are the way to tell us.
What is on the site
- 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 rule
- Board Feet to Weight Converter - Convert board feet to pounds — by species, moisture content, and surfacing.
- Board Foot Calculator with Waste & Defect Allowance - Estimate board feet for hardwood, softwood, or project packs — including realistic waste, defect, and planing
- Compound Miter & Bevel Angle Calculator - Get the miter and bevel angles for a compound cut — crown molding, picture framing, sloped soffits.
- Cord of Firewood Calculator - Convert stacked volume to face cord, full cord, cubic feet, and approximate weight — by species.
- DIY vs Buy-it Cost Calculator - Decide whether to make it yourself or buy it — by your hourly rate, materials, and tool amortization.
- Dowel Joint Spacing & Quantity Calculator - Plan dowel diameter, count, and spacing for edge-to-edge or edge-to-face joints.
- 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 mach
- 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
- Floor Joist Span Calculator - Check allowable spans for floor joists by species, grade, spacing, and deflection limit.
- Linear Feet ↔ Board Feet Converter - Translate between running feet of a known cross-section and board feet — useful for trim, decking, and 2× lumb
- Log Volume Calculator (Doyle / Scribner / International) - Estimate log board-foot volume using three scaling rules — and see how Doyle famously under-counts small logs.
- 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.
- Mortise & Tenon Dimension Calculator - Size mortise width, tenon thickness, and shoulder length to your stock — with a rule-of-thumb that avoids weak
- 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
- Offcut Reuse Planner - Tell it your parts and your scrap pile, and find which offcuts can become a new project — no extra lumber need
- 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
- 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 bookc
- Pocket Hole Spacing & Screw Selector - Pick the right Kreg-style pocket hole spacing for face frames, cabinet carcases, and edge-to-face joinery — wi
- Polyurethane / Varnish Coverage Calculator - Calculate how much poly, varnish, or hardwax oil you need — by surface area, coats, and product type.
- Rafter Length & Birdsmouth Calculator - Compute common rafter length, birdsmouth plumb and seat cuts, and overhang — from rise/run and pitch.
- Sandpaper Grit Progression Selector - Pick the right grits for your sanding job — from rough stock removal to final finishing — and don't waste step
- Saw Blade Kerf & Material Waste Calculator - Quantify the wood lost to kerf across many cuts, and compare a thin-kerf vs full-kerf blade.
- Wood Screw Pull-out & Shear Estimator - Estimate withdrawal load and shear capacity for a wood screw by species, diameter, and embedment depth.
- Shelf Sag & Load Capacity Calculator - Predict how much a shelf will sag under a distributed load — and the maximum load before the shelf looks unhap
- Wood Stain Coverage Calculator with Coat Count - Estimate how many quarts/gallons of stain you need — by surface area, coats, wood porosity, and waste.
- Stair Stringer Calculator (Rise / Run / Code Check) - Plan a stair stringer: rise, run, number of treads, headroom, and IRC code check.
- 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 Acclimation Timeline Estimator - Estimate how long your lumber should sit in the shop before milling — based on species, board thickness, and m
- Pre-Stain Wood Conditioner Coverage - Estimate conditioner needs for blotch-prone woods — pine, cherry, birch, maple — before stain or dye.
- Wood Movement Calculator (Seasonal) - Predict how much a solid wood panel will expand or contract across seasons — across the grain, not along it.
- Workshop Air Exchange Calculator - Estimate CFM of fresh-air ventilation needed for your shop, plus recommended filter change schedule.
Questions
Do the tools need an account or a payment?
No. Every tool on Carpentry Hub is free, needs no account, and works before you type anything personal. The numbers you enter are used by the calculation on the current page and are gone when you reload.
Can I treat the output as a final answer?
Not on its own. A tool returns a magnitude under the conditions you typed in. It does not include what it costs to act, what might change while you act, or how the other side behaves. Before spending money, signing, or promising something to a third party, check the result against the source material and the official position.
What is the most reliable way to use these tools?
Follow the order given in the usage section: get your figures onto the same basis first, fill in one field at a time, then calculate. Checking that every unit matches the thing you are actually measuring catches more wrong answers than any other habit, and it takes about ten seconds.
My number does not match what I expected. What should I check?
Three things: that the units agree, that you have not left an optional field blank and accepted its default, and that you recalculated after editing an input. If all three are fine, the likely explanation is that your basis differs from the one the tool assumes - the limitations section on each tool page says what it covers.
Will the pages stay available?
We try to keep them, but the premises of a tool, the reference data and the outside world all move. Pages get reviewed and corrected as that happens. If you need to keep a result long term, take a screenshot and record the inputs you used.
Scope and limitations
This page describes what the tools on this site are built to do. A common mistake is to read a short explanation and treat it as an official specification 鈥?it is not. Every tool here is a calculation aid: it works from the numbers you type in, and it cannot verify whether those numbers are correct, current, or appropriate for your situation.
Where this stops: the tools give you a number and the reasoning behind it. They do not replace professional advice, and they do not know anything about your specific case. Where a decision carries legal, financial, safety or health consequences, check the relevant official source before acting on anything you read here.