Timber & Lumber Calculator – Boards, Lengths, Waste, Volume & Cost
Timber & Lumber Calculator
Free timber & lumber calculator for boards, stock lengths, waste, volume, board feet and cost. Metric and Imperial for tradespeople and DIY..
Project Settings
Give the job a name, then choose your measurement system and currency.
Timber / Lumber Sections
Add one section for each different timber size, stock length or part of the project.
Labour & Project Costs
Optional. Leave these fields at 0 if you only want a timber/material estimate.
Your detailed quantities, timber volume, board feet and cost breakdown will appear below.
Your Timber & Lumber Estimate
Material quantities, purchased stock, timber volume, costs and job pricing.
Enter your timber details above and select Calculate Timber & Project Estimate.
Timber / Lumber Breakdown
Each timber size or section is calculated separately before being added to the project totals.
Project Cost Breakdown
Optional pricing fields remain at zero when the calculator is being used only as a material estimator.
| Timber / lumber material cost | £0.00 |
| Labour cost | £0.00 |
| Additional costs | £0.00 |
| Total project cost | £0.00 |
| Markup | £0.00 |
| Selling price before tax | £0.00 |
| VAT / Sales Tax | £0.00 |
| Recommended Customer Price | £0.00 |
Your Job Score
A simple check of whether important pricing allowances have been included.
Turn Your Estimate Into a Professional Quote
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Create quotes and invoices whenever you need them. No subscription required.
Timber & Lumber Calculator for Boards, Lengths, Waste, Volume & Cost
This free timber and lumber calculator helps tradespeople, contractors, builders and DIY users estimate how much timber is required for a project. Enter the finished lengths you need, the available stock board length, timber dimensions and a waste allowance, and the calculator estimates the number of boards to buy.
It can also calculate total purchased length, timber volume, board feet, material cost, labour cost, markup and tax. Metric and Imperial measurements are supported, making the calculator useful for timber estimating in the UK as well as lumber calculations in the United States, Canada and other markets.
What Does the Timber Calculator Work Out?
Timber is often sold in standard stock lengths rather than the exact finished lengths required for a job. Simply adding together the finished dimensions can therefore underestimate the amount you need to purchase. This calculator adds your chosen waste allowance and rounds the result up to whole purchasable stock pieces.
Boards or Pieces Required
Estimates the number of full-length stock boards that should be purchased based on the required length, quantity, stock length and waste percentage.
Total Purchased Length
Shows the total linear amount of timber or lumber being bought after quantities have been rounded to whole stock lengths.
Timber Volume
Uses the width, thickness and purchased length to calculate the approximate volume of timber in cubic metres or cubic feet.
Board Feet
Provides a board-foot estimate for users who purchase or compare lumber by board-foot volume, particularly in North America.
Waste and Surplus
Separates your deliberate waste allowance from the expected surplus created when complete stock boards must be purchased.
Project Pricing
Optional labour, additional costs, markup and VAT or sales tax can be added to produce a more complete estimated job price.
What Projects Can You Use It For?
The calculator can be used wherever timber or lumber is being bought in standard lengths. Different sizes of timber can be entered as separate sections, making it useful for jobs containing more than one timber dimension.
- Timber framing and stud walls
- Floor joists and ceiling joists
- Roof battens and timber framing
- Decking subframes and bearers
- Fence rails and timber supports
- Garden structures and pergolas
- Shelving and workshop projects
- Joinery and carpentry estimating
- Timber repairs and refurbishment
- General construction projects
How Much Waste Should You Allow for Timber?
There is no single waste percentage that is correct for every job. Straightforward projects using repeatable lengths may produce very little waste, while projects with many short cuts, angles, defects or complicated cutting patterns may require considerably more.
A starting allowance of around 5% to 10% is often useful for straightforward estimating, but the correct amount should be based on the actual project. Timber containing knots, splits, damaged ends or unacceptable grain may also increase the amount that needs to be purchased.
Practical tip: Do not automatically treat every leftover piece as waste. Longer offcuts may be reusable elsewhere on the project. Looking at the actual cutting sequence can sometimes reduce the number of boards that need to be purchased.
What Is a Board Foot?
A board foot is a measure of lumber volume commonly used in the United States and Canada. One board foot represents a piece of lumber measuring approximately 1 inch thick, 12 inches wide and 12 inches long.
For example, a nominal piece measuring 2 inches thick × 6 inches wide × 8 feet long represents 8 board feet using those dimensions. Ten identical pieces would therefore represent approximately 80 board feet.
The calculator automatically displays board feet alongside the purchased timber volume, so users can compare lumber quantities without carrying out the conversion manually.
Calculating Timber and Lumber Cost
Timber suppliers do not always price material in the same way. Depending on the product and supplier, timber may be priced by the individual board, by linear length or by volume. The calculator therefore provides several pricing options.
Price Per Board or Piece
Useful when your supplier gives a fixed price for each stock length. The calculator multiplies the price by the number of complete boards required.
Price Per Linear Metre or Foot
Useful when material is priced according to linear length. Cost is calculated from the total stock length being purchased.
Price by Timber Volume
Useful where timber is sold according to cubic metres or cubic feet. The purchased volume is multiplied by the entered rate.
Labour and Job Pricing
Contractors can optionally add labour, additional costs, percentage markup and tax to estimate a customer selling price.
Markup and margin are not the same. This calculator applies markup to the estimated project cost. For example, a £100 project cost with 25% markup produces a selling price of £125 before tax.
Timber Cutting and Offcut Limitations
This calculator is designed as a practical material estimator rather than a full cutting-stock optimisation program. Real timber cutting can be affected by saw kerf, required cut orientation, damaged ends, timber defects, grain direction and whether offcuts can be reused.
For complex joinery or projects containing many different cut lengths, preparing a separate cutting list before ordering material is recommended. The calculator should be used to support planning, not replace checking the actual cutting layout.
Timber & Lumber Calculator FAQs
How do I calculate how many timber boards I need?
Enter the required finished length, quantity of runs or pieces, available stock board length and your chosen waste percentage. The calculator works out the total required length and rounds the stock requirement upward to whole boards.
Should I add waste when calculating timber?
Usually yes. Waste can occur because of cutting, damaged ends, unsuitable defects and stock-length restrictions. The appropriate waste percentage depends on the type of work and how efficiently the timber can be cut.
What is the difference between required length and purchased length?
Required length is the timber needed in the finished project. Purchased length is the amount of complete stock timber that must actually be bought after waste and whole-board rounding have been taken into account.
Can I calculate different timber sizes in one project?
Yes. Add another timber section for each different size or type of timber. The calculator shows the result for each section individually and also creates combined project totals.
Does the calculator work in feet and inches?
Yes. Switch the calculator to Imperial mode to enter lengths in feet and timber width and thickness in inches. The results include linear feet, cubic feet and board feet.
Does the calculator work in metres and millimetres?
Yes. Metric mode uses metres for timber lengths and millimetres for width and thickness. Timber volume is then calculated in cubic metres.
Can I use this calculator to price a carpentry or timber job?
Yes. Material prices can be combined with optional labour, additional expenses, markup and VAT or sales tax. The result provides an estimated customer price that can be used as a starting point when preparing a quote.
Does this calculator optimise the best cutting layout?
No. It estimates stock quantities but is not a full cut-list optimisation tool. Complex projects should still be checked against an actual cutting schedule before material is ordered.
More Free Trade Calculators
Planning or pricing another job? Try some of the other free calculators available on The Handyman Hub.