Cut List Optimizer
Simple Board Feet Calculator
Nominal vs Actual Lumber Dimensions
Lumber is sold in nominal sizes, but after drying and planing at the mill, the actual dimensions are smaller. Use the actual dimensions in your calculations.
1x Boards (Actual Thickness 3/4")
| Nominal | Actual Width |
|---|---|
| 1x2 | 1.5" |
| 1x4 | 3.5" |
| 1x6 | 5.5" |
| 1x8 | 7.25" |
| 1x10 | 9.25" |
| 1x12 | 11.25" |
2x Boards (Actual Thickness 1.5")
| Nominal | Actual Width |
|---|---|
| 2x4 | 3.5" |
| 2x6 | 5.5" |
| 2x8 | 7.25" |
| 2x10 | 9.25" |
| 2x12 | 11.25" |
4x Timbers (Actual Thickness 3.5")
| Nominal | Actual Width |
|---|---|
| 4x4 | 3.5" |
| 4x6 | 5.5" |
| 4x8 | 7.25" |
Large Timbers
| Nominal | Actual Size |
|---|---|
| 6x6 | 5.5" x 5.5" |
| 8x8 | 7.25" x 7.25" |
Source: Standard North American lumber milling (verified against hardwood and softwood grade standards).
How Board Feet Works
The Formula
One board foot = one square foot of wood one inch thick. To calculate: (length in feet) x (width in inches) x (thickness in inches) / 12.
Example: A board 8 feet long, 6 inches wide, 1 inch thick = 8 x 6 x 1 / 12 = 4 board feet.
Why Kerf Matters
Saw kerf is the width of material your blade removes on every cut. A standard table saw blade has about 1/8 inch kerf. On a project with 10 cuts, that is 1.25 inches of material gone. On a 42-part cabinet, kerf loss can add up to a quarter sheet of plywood.
You need three pieces: 24", 24", and 12" long, each 5.5" wide, 1" thick (nominal 1x6 boards).
Without kerf accounting: You might buy one 96" board (8 feet). The pieces use 24+24+12 = 60 inches, with 36 inches left. Looks fine.
With kerf accounting (1/8" blade, 2 cuts): The blade removes 0.25" on each cut. To cut 24, 24, and 12 inches, you need: 24 + 1/8 + 24 + 1/8 + 12 = 60.25 inches. Now you need a second board because you did not account for the material the blade eats. The optimizer handles this automatically.
Cut List Optimizer Algorithm
The optimizer uses a first-fit-decreasing approach: sort your pieces longest-first, then fit them onto boards one at a time, accounting for kerf. This is fast to calculate and works well for most hobby projects. Professional woodworkers sometimes use more sophisticated nesting software for complex projects with many different sizes.
Thin Kerf vs Standard Blades
A thin-kerf blade (0.06 to 0.091 inch) wastes 30-50% less material than a standard blade (0.125 inch). On a big project, the payoff can justify the cost. Check your blade's product label or spec sheet for its kerf width, or measure the blade thickness with calipers.