Free woodworking maths
Woodworking and Carpentry Maths Toolkit
Fast, plain-English calculators and guides for estimating lumber/timber, board feet, sheets, decks, stairs, rafters, miters, wood weight, costs, and cut lists.
Plan material quantities with less guesswork
This site is for DIY builders, woodworkers, carpenters, contractors, furniture makers, and anyone who needs quick project maths before buying boards, panels, or hardware. The tools are free and focused on practical estimating, not accounts, subscriptions, or paywalls.
What you can estimate
- Board feet, linear feet, and lumber/timber cost comparisons.
- Sheet goods, deck boards, stair stringers, rafters, and miters.
- Cut lists, wood weight, waste allowance, and early buying quantities.
Popular calculators
Start with the core project-planning tools.
Board Foot Calculator
Estimate lumber/timber volume from thickness, width, length, and quantity. Use it when comparing boards, planning material purchases, or checking rough stock requirements before a project.
Lumber/Timber Cost Calculator
Estimate lumber/timber material cost from quantity, unit price, waste, and optional extra allowance. Use it when comparing supplier prices, budgeting a project, or checking whether a material order fits your plan.
Nominal to Actual Lumber Size Calculator
Compare selected North American softwood nominal labels with sourced dressed-size references or measured custom dimensions for planning and volume estimates.
Sheet Goods Calculator
Estimate plywood, MDF, OSB, and panel quantities for cabinets, furniture, and site work.
Deck Board Calculator
Estimate deck board quantities from deck size, board width, gaps, stock length, layout direction, waste, and optional material costs.
Fence Board Calculator
Estimate complete pre-cut fence boards or pickets, posts, rails, waste, and optional entered-material cost.
Practical guides
Clear explanations before you open a calculator.
How to Calculate Board Feet
Understand board-foot volume and use it to organize mixed-size lumber purchases.
Board Feet vs Linear Feet
Understand the difference between volume pricing and length pricing for wood projects.
Nominal vs Actual Lumber Sizes
Understand North American nominal lumber labels, surfaced sizes, and when to measure stock.
How to Estimate Sheet Goods
Understand area estimates, whole-sheet rounding, and layout constraints for sheet goods.
Why these numbers can be checked
Most project maths is simple arithmetic wrapped around conventions that are easy to get wrong: nominal versus actual sizes, board feet versus linear feet, saw kerf, waste allowance, seasonal movement. A calculator that hides those conventions is not saving you time — it is moving the error somewhere you cannot see it.
Sourced reference data
Dressed sizes, species density and shrinkage values come from published standards and government research, each recording its issuing body, table and verification date.
Stated scope limits
Every tool says what it models and what it does not. Structural adequacy, safety requirements and local building rules are explicitly outside these estimates.
Dated and reviewed
All 11 guides carry a publication date, a review date and the list of publications behind their figures.