A cut list only works when you translate its lumber names into the boards you can actually buy. A 2x4 is usually 1-1/2 by 3-1/2 inches, not 2 by 4. A 1x6 is commonly 3/4 by 5-1/2 inches. And a sheet sold as 3/4-inch plywood may be closer to 23/32 inch thick. Use the nominal name to find the material, then use the measured size to lay out parts, set joinery, and decide how much stock to buy.
That small distinction prevents a lot of frustrating mistakes. A shelf can wind up narrower than the plan, a dado can be loose, or the last part on a board can come up short. Read the cut list first, measure the stock second, and make the cuts after the numbers agree.
Start by separating the material list from the part sizes
Most plans use two different kinds of dimensions:
- The material list names what to buy, often by nominal size: 2x4, 1x6, or 3/4-inch plywood.
- The cut list gives the finished size of each part: length, width, thickness, and quantity.
Those are not interchangeable. The material list might call for a 1x6, while the cut list expects a part that is 5-1/2 inches wide. That is normal. Kreg's lumber guide uses the same distinction: the label tells you the nominal size, while project dimensions should use the actual board size.
If a plan only says "cut two pieces from a 1x6" and does not give a finished width, pause before cutting. Check the drawing, joinery, and any assembly dimensions. A good plan should tell you which measurements control the build.
Nominal and actual lumber sizes at a glance
For common surfaced softwood boards in the U.S., these are useful planning references:
| Material sold as | Typical actual size | Use this number for |
|---|---|---|
| 2x4 | 1-1/2 x 3-1/2 in. | Part widths, frame openings, and joinery |
| 1x6 | 3/4 x 5-1/2 in. | Part thickness and shelf or rail width |
| 3/4-in. plywood | Often about 23/32 in. thick | Dados, rabbets, and panel fit |
| 4/4 hardwood | Roughly 1 in. before milling | Planning material to surface to final thickness |
The first two rows are standard dressed-dimension examples, not a promise about every board in every market. Lowe's nominal-versus-actual guide and Kreg's buying guide both show why a board's store name differs from its finished measurement.
The difference comes from milling. Softwood dimensional lumber is cut, dried, and surfaced before sale, which leaves it smaller than its original rough size. Hardwood is often sold in quarter thicknesses instead. A 4/4 board starts around one inch thick, but the thickness you can keep after flattening and planing depends on the board and how much material it needs to lose.
Plywood needs its own check. The label is a shopping category, not a joinery setting. Measure the sheet with calipers before cutting a dado or making a spacer. One sheet may be close to 23/32 inch, while another product can be different enough to affect a snug fit.
Put actual measurements in the cut list
Once you have the stock in front of you, make a working cut list with the dimensions that matter at the saw. Include these columns:
| Part | Quantity | Finished size | Stock | Notes |
|---|---|---|---|---|
| Side | 2 | 18 x 5-1/2 x 3/4 in. | 1x6 | Check for straight grain |
| Shelf | 3 | 24 x 5-1/2 x 3/4 in. | 1x6 | Keep the best faces visible |
This is also the moment to check whether the plan's stated thickness matches your material. A plan designed around true 3/4-inch plywood can change when your sheet measures smaller. Let the stock you are using set the width of matching grooves and rebates whenever the joint permits it.
For a simple layout, list the longest pieces first. They are hardest to place and leave the most awkward offcuts. A cut-list calculator can help with a larger batch, but enter the actual stock length and the kerf from your saw. KerfWorks explains that the blade removes material between adjacent pieces, so a layout that looks perfect on paper can still fail by a few fractions of an inch.
Add kerf, trim, and defects before you buy
Kerf is the width of material a blade removes. It is not a mysterious extra allowance. It is the strip of wood that turns to sawdust with each separating cut.
When several parts come from one board, add a kerf between adjacent parts. Four parts in a row need three planned separations. Then leave room for an end trim if the board is rough, damaged, or not square. The kerf varies by blade and saw, so use your setup's measurement instead of borrowing a number from a plan.
Do not treat every inch of a board as usable. Look for knots, checks, wane, twist, cup, and ugly grain before you commit a layout. Kreg's guide recommends sorting boards for flatness and defects rather than taking the first ones off the rack. If a project needs clean visible parts, reserve more material than a shop jig would need.
There is no universal waste percentage. The right allowance depends on the project, stock quality, grain matching, and whether you can use offcuts later. For a small beginner project, an extra board is often cheaper than a second trip and a stalled glue-up. For a larger batch, lay out every part first and buy to that layout.
Worked example: a small 1x6 wall organizer
Say you are building a simple open wall organizer from nominal 1x6 boards. The plan calls for two 18-inch sides and three 24-inch shelves. At the store, your boards measure 3/4 by 5-1/2 inches. That means the finished pieces will all be 5-1/2 inches wide unless you rip them narrower.
The part lengths are:
- Two sides at 18 inches: 36 inches total
- Three shelves at 24 inches: 72 inches total
The parts alone need 108 inches. If you place the five parts in a row, there are four gaps between them. With a 1/8-inch kerf, add 1/2 inch. Add about four more inches for trimming a rough end, avoiding a small defect, and leaving yourself a little breathing room.
108 + 1/2 + 4 = 112-1/2 inches
Two 6-foot boards give you 144 inches of stock, so they are a comfortable buy for this layout. One 10-foot board gives you only 120 inches and may work if it is straight, clean, and a true full length, but it leaves little room for an end trim or a bad knot. That is a choice to make after inspecting the board, not a number to trust blindly.
This example is deliberately simple. It does not include miter waste, grain matching, wide-panel glue-ups, or milling rough lumber. Those details each need their own allowance. The habit stays the same: add the finished parts, add the cuts, inspect the stock, then choose the buy list.
Rough-sawn, surfaced, and sheet goods are different cases
Nominal softwood boards, rough hardwood, and plywood should not share one shortcut.
- Nominal softwood: use the usual actual dimensions as a starting point, then confirm the board you bought.
- Rough hardwood: buy enough thickness and width to flatten, straighten, and plane it to final size. A 4/4 label does not guarantee a finished one-inch part.
- Plywood and other sheet goods: measure thickness at the sheet, especially when a joint depends on it. Do not assume a 3/4-inch router bit makes a perfect plywood dado.
If your plan came from another country, uses metric stock, or specifies a named sheet product, do not force it into a U.S. nominal chart. Convert the design carefully and buy material by its actual local dimensions.
Before the first cut
Run through this short check before turning on the saw:
- Confirm which numbers in the plan are nominal material names and which are finished part dimensions.
- Measure the thickness and width of the stock you will use.
- Check plywood with calipers before sizing a groove or spacer.
- Lay out the longest parts first and add the kerf between pieces.
- Mark defects and allow for trimming before finalizing the buy list.
- Re-measure the first cut part before cutting the rest of a batch.
Accurate planning is a small-shop advantage. It keeps material costs under control and makes repeat work less stressful. Let the stock you bought—not the label—set the last dimensions before you make the first cut.