A woodworking plan packs a lot of information into a few pages. Once you know where to look, it reads like a recipe: here is what to buy, here is how to cut it, here is the order to put it together.
This guide walks through each part of a typical plan, the notation you will see, and a simple routine for checking a plan before you spend money on lumber.
The parts of a typical plan
- Overview: a picture or drawing of the finished project with its overall size (width x height x depth).
- Tools list: what you need. If a tool you do not own is listed, look for a workaround before you start.
- Materials or shopping list: boards by nominal size and length (for example, "2 pcs 1x10 x 8 ft"), sheet goods, hardware and finish.
- Cut list: every individual part with its quantity and finished dimensions.
- Drawings: views of the project with dimensions, plus details of tricky joints.
- Steps: the assembly order. The order matters: some screws can only be reached before another part goes on.
Understanding the drawings
- Front, side and top views show the project flat, as if you were looking straight at it from each direction. Measurements are easiest to read here.
- Exploded view: parts pulled apart in 3D so you can see how they fit together. Parts are usually labeled with letters that match the cut list.
- Detail views: close ups of a joint, a notch or a hole location.
- Dimension lines have arrows or ticks at each end. The number between them is the distance between those two points, not necessarily the size of a part.
How dimensions are written
In US plans, dimensions are in inches and fractions: 1-1/2" means one and a half inches. Feet are marked with a single quote: 8' is eight feet.
Part sizes are usually listed in this order: thickness x width x length. So a shelf listed as 3/4" x 9-1/4" x 22-1/2" is 3/4" thick, 9-1/4" wide and 22-1/2" long. Length normally runs along the grain.
Nominal vs actual lumber sizes
This trips up nearly every beginner. Lumber is sold by a nominal name that is bigger than the real board. A "2x4" is actually 1-1/2" x 3-1/2". Good plans use the actual size in their dimensions and the nominal name only in the shopping list.
| Nominal | Actual size | Nominal | Actual size |
|---|---|---|---|
| 1x2 | 3/4" x 1-1/2" | 1x10 | 3/4" x 9-1/4" |
| 1x3 | 3/4" x 2-1/2" | 1x12 | 3/4" x 11-1/4" |
| 1x4 | 3/4" x 3-1/2" | 2x2 | 1-1/2" x 1-1/2" |
| 1x6 | 3/4" x 5-1/2" | 2x4 | 1-1/2" x 3-1/2" |
| 1x8 | 3/4" x 7-1/4" | 2x6 | 1-1/2" x 5-1/2" |
Plywood is similar: a sheet sold as 3/4" is often 23/32" thick. Measure before you cut grooves or set spacings.
Common abbreviations
| Abbreviation | Meaning |
|---|---|
| T, W, L | Thickness, width, length |
| Qty or pcs | Quantity, pieces |
| OC | On center: measured from the center of one part to the center of the next |
| S4S | Surfaced four sides: smooth, ready to use boards |
| PT | Pressure treated lumber |
| Ply | Plywood |
| Dia. | Diameter (holes, dowels) |
| CTF or "cut to fit" | Measure the assembled project and cut this part to match |
Read the cut list like a pro
Each row in a cut list is one part: a letter, a name, a quantity and three dimensions. Before you buy anything, do a quick sanity check on the math. For example, in a bookcase that is 24" wide with 3/4" sides, the shelves must be 24" minus 3/4" minus 3/4", which is 22-1/2". If the numbers do not add up, the plan has an error or assumes a different board thickness.
Next, check that the parts fit on the boards in the shopping list. Our guide on how to make a cut list shows how to lay parts out on a board, including the 1/8" the saw blade removes with every cut.
A five step routine before you cut
- Read the whole plan twice, start to finish, before buying anything.
- Check the math on a few key parts, like shelves and rails.
- Measure your actual lumber. Store boards vary slightly, and the plan may assume a different thickness.
- Label every part with its letter in pencil as you cut it.
- Dry fit the parts with clamps before glue or screws. Fixing a mistake is easy now and hard later.
Signs of a weak plan
- No cut list, or a cut list that uses nominal sizes as if they were real
- Measurements that do not add up
- No assembly order, or steps that skip how parts are fastened
- Blurry drawings where you cannot read the numbers
None of these make a plan useless, but they mean you will need to work out more yourself. Practice on the plans in our free PDF: each one lists parts with letters, actual sizes and the board layout.