Reading a Materials List: Nominal vs Actual Sizes, Board Feet and How Much Extra Lumber to Buy

A materials list looks like a shopping list, but it is really a set of assumptions about which sizes the author means and how much waste they expect. If you misread it, you can come home with boards that are too thin, too few, or the wrong kind. Here is what to check before you buy anything, whether the list comes from a paid pack, a free PDF or a magazine.

Nominal vs actual sizes

In North American lumber yards, a "2x4" is not 2 by 4 inches. The nominal name describes the rough board before drying and planing. What you carry out is smaller. Many plans list nominal names in the materials list but use actual sizes in the cut list, and some mix the two without saying so.

Common softwood sizes

Treat these as typical, not guaranteed. Measure the boards at the store with a tape or calipers. Lengths are usually true to the label, or slightly over.

Hardwood works differently

Hardwood is usually sold by thickness in quarters of an inch: 4/4 (four-quarter) is roughly 1" rough, 5/4 is about 1-1/4", and 8/4 is about 2". If the yard has surfaced it, a 4/4 board often ends up around 13/16" or 3/4". Widths are random and vary board to board. A plan that says "1×6 oak" may mean a surfaced board, or may expect you to mill rough stock yourself. Ask the yard what you are buying.

Metric plans and imported plans

If the plan uses millimetres, or the author works in another country, the stock sizes may not match what your local yard carries. Do not just convert and hope. Match the finished dimension you need to the closest stock you can actually buy, then adjust joinery where necessary. The guide on adjusting a plan's dimensions covers how to do that without breaking proportions.

Board feet in plain terms

Hardwood is commonly priced by the board foot, which is a volume measure. The formula:

Thickness (in) × Width (in) × Length (ft) ÷ 12 = board feet

For example, a 1" × 6" × 8' board is 1 × 6 × 8 ÷ 12 = 4 board feet. Use the nominal thickness (1" for 4/4), and the width and length you are buying, not the finished size.

How to do it for a whole project

1. List every part from the cut list with its finished thickness, width and length.
2. Round each part up to the stock thickness you would actually buy (a 3/4" part comes from 4/4 stock, a 1-1/2" part from 8/4).
3. Group parts by thickness, since each group is bought and priced separately.
4. Add up the board feet for each group, then add your waste allowance (below).
5. Ask the yard for the current price per board foot. Prices vary by species, grade and region, so do not rely on any figure printed in a plan.

How much extra lumber to buy

There is no single correct number. Many woodworkers add roughly 15 to 20 percent as a starting point for solid wood. That is a rule of thumb, not a guarantee. Adjust it for these factors:

• Board quality. Knots, checks, wane and warp mean you cut around defects. Hand-picking boards at the yard reduces waste but takes time.
• Grain and appearance. Visible parts like tabletops and door panels may need matched grain, which costs extra length.
• Your experience. A first project usually produces more mistakes. Buying a little more is cheaper than a second trip, and one wrong cut will not sink the project.
• Cutting layout. Long parts from short boards waste more. Check whether your cut list can be nested efficiently on the board lengths available.
• Sheet goods. Plywood is sold in fixed sheets (commonly 4' × 8'). Sketch a layout. A list that says "1 sheet" may not fit all the parts once you allow for saw kerf.

Where extra is not worth it

For construction lumber like 2×4s, extra is cheap and often useful, since the best boards in a bin are not always the straightest. For expensive hardwood, extra adds up quickly. In that case, buy a modest margin and plan your cuts carefully, perhaps cutting the most critical parts first.

Recommended for youWhy Woodworking Builds Fail: Common Causes and How Better Plans Prevent Them

Checks to run on any materials list

• Do the totals match the cut list? Add up the parts yourself. Mismatches are a common sign of a rushed plan.
• Is it nominal or actual? If the plan does not say, assume nothing and compare against the drawings.
• Is hardware included? Screws, glue, finish, hinges and sandpaper are often missing or vague.
• Is the species stated? This matters for cost and for outdoor use. See building outdoor projects from plans for wood choice and weatherproofing.
• Does the plan assume tools you lack? Some lists assume you will mill rough lumber or rip boards to width. The starter tool kit guide and the question on whether you need a table saw are worth reading first.

Free plans vs paid plan packs

Free plans can be perfectly good, but materials lists are where errors tend to show up, so check them with the steps above. Our page on whether free plan PDFs are accurate goes into this. With any paid pack, including Teds Woodworking, check on the official site what the materials lists actually include. Look for whether they give nominal or actual sizes, whether they include hardware, and whether the cut lists are complete. Do not assume this from a sales page. Our guide to finding good woodworking plans explains what to look for when comparing options.

If the list turns out to be wrong

It happens, even with good plans. If you find a missing part or a mismatched dimension before cutting, stop and work it out on paper. If you are already mid-build, see rescuing a build from a bad or incomplete plan. For the bigger picture, why woodworking builds fail shows how often materials mistakes are the cause. If you are unsure about a large purchase, asking a local woodworker or taking a class can save you real money.

Before you go to the yard

1. Work out your own list from the cut list, with actual sizes.
2. Convert it to stock sizes and lengths you can really buy.
3. Add a waste allowance that fits the wood and your experience.
4. Bring a tape measure and your cut list so you can check boards on the spot.
5. Check the current price, since it changes. For budgeting ideas, see furniture projects that save the most money. For the wider planning process, see how to plan a project before you buy lumber. For time, see how long a first build takes.

Keep reading

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