Lumber can be priced by the board, by the linear foot, by the board foot, or by a package. Each unit answers a different question. A low number on one quote may be more expensive than a higher number on another if the billing units differ. Before comparing suppliers, identify the dimensions used for billing, the stock lengths supplied, and any surfacing or delivery charges. Then convert both quotes to the same finished requirement. The distinctions below help you calculate rough hardwood volume, trim length, finished coverage, and an initial material cost without confusing nominal names with measured wood.
The same board has three different useful measurements
| Example actual board: 1 × 6 in × 8 ft | Calculation | Quantity |
|---|---|---|
| Linear measure | Length only | 8 linear ft |
| One wide face | 8 × 6 ÷ 12 | 4 sq ft |
| Board-foot volume | 1 × 6 × 8 ÷ 12 | 4 board ft |
Numerical examples are illustrative. Product yields, installation requirements and supplier packaging must be checked for the material you choose.
A linear foot is length of a specified product
One linear foot is one foot measured along a piece. It does not describe the piece’s width or thickness. Ten linear feet of a narrow molding and ten linear feet of a wide shelf have the same length but very different wood volume. A linear-foot price is meaningful only when the product profile, dimensions, grade, and finish are stated.
Calculation exampleFor a trim takeoff, add the required cut lengths. Six 8-foot lengths, four 4-foot lengths, and a separate 10-foot run total 74 linear feet. That total is useful for estimating material, but it does not prove how many stock pieces will yield all cuts. Individual long pieces, kerf, joints, and defects still matter.
A board foot is a volume unit
A board foot contains 144 cubic inches of wood. The familiar calculation uses thickness in inches times width in inches times length in feet, divided by 12. A board billed at 1 inch thick, 6 inches wide, and 8 feet long therefore contains 4 board feet. Ten identical boards contain 40 board feet.
At an entered price of $5 per board foot, that order’s wood subtotal is $200 before any additional charges. This is an illustrative rate, not a market quote. A thicker board with the same width and length contains more board feet, so the same price per board foot produces a larger per-board cost. Confirm the dimensions and tally rules used by the seller.
Nominal size, actual size and billed size can differ
A nominal lumber name identifies a product category; it is not always the finished measured section. Surfacing removes material, and moisture condition or manufacturing conventions can also affect dimensions. For weight and geometric fit, use actual dimensions. For a supplier’s board-foot bill, use the dimensions on which that supplier actually bases the tally.
Do not silently use a smaller finished measurement to challenge a quote based on rough billing dimensions. Instead, ask how thickness, width, and length are tallied, whether increments are rounded, and which milling services are included. A useful comparison lists the rough volume purchased, the finished dimensions expected, and any additional surfacing cost as separate facts.
Square feet describe surface coverage
Square footage measures area and cannot be converted to linear footage without a coverage width. At 6 inches of effective coverage, a board covers half a square foot per linear foot, so 100 square feet requires 200 linear feet before layout losses. If part of the width is hidden by overlap, coverage is smaller and the required length increases.
For example, a 6-inch actual face with a 0.5-inch overlap has 5.5 inches of effective width. Covering 200 square feet requires 200 times 12 divided by 5.5, or approximately 436.364 linear feet. If the manufacturer already states net installed coverage width, enter that figure directly and do not deduct the overlap a second time.
Whole-board purchasing changes the final bill
Suppose your finished requirement is 100 linear feet and you choose an illustrative 10 percent cutting allowance. The adjusted length is 110 feet. In 8-foot stock, a simple total-length estimate rounds that to 14 boards, or 112 purchased feet. At $9 per board, the material subtotal is $126.
A stock-length comparison should use the actual price per board and a cut plan. A 12-foot board that appears more expensive per piece may yield the parts more efficiently. Conversely, a long stock length can create handling difficulties or unusable offcuts. Check whether every required unbroken length fits before comparing only the total purchased footage.
Usable yield is different from purchased volume
Rough boards can include end checks, knots, sapwood exclusions, or sections that do not fit the project’s appearance requirements. Milling removes thickness and width. Cutting consumes kerf and leaves offcuts. These losses are not all represented by a single nominal dimension change. A finished cutting list helps identify how much sound stock is needed in each width and length.
For a first estimate, keep the allowance visible and identify its purpose. An extra percentage for defects should not be accidentally added again inside a supplier quantity already carrying the same allowance. When a project has expensive or wide parts, inspect the available boards and plan those pieces first. A total board-foot figure alone does not guarantee the necessary widths.
Use density carefully when planning transport
Board feet can be converted to cubic feet by dividing by 12. To estimate weight, multiply actual solid volume by a density appropriate to the wood and its moisture condition. Twenty boards measuring 1.5 by 5.5 inches by 8 feet total about 9.1667 cubic feet. At an assumed 35 pounds per cubic foot, the wood would weigh about 320.83 pounds.
The density in that example is a supplied assumption, not a universal lumber weight. Wet or treated stock can differ, and packaging adds more weight. Obtain a supplier shipping weight when possible, especially when close to a handling or transport limit. Vehicle payload, axle limits, load distribution, and securement are separate checks.
Compare quotes on one clear purchase basis
Create one short comparison for each supplier: product specification, billed unit, billed dimensions, supplied stock lengths, quantity, milling charge, material tax, and delivery. Convert the material subtotal to the same project requirement rather than comparing the headline unit price alone. Confirm whether tax is already included before adding it again.
Keep rough volume, finished dimensions, and coverage as separate columns. This makes the reason for each conversion visible and helps avoid errors when the project changes. A clear quote comparison also makes it easier to substitute a stock length or profile later: you can update the relevant line instead of rebuilding the entire estimate from an unexplained total.
Questions before you order
Is a board foot the same as a square foot?
No. A board foot is volume; a square foot is area. They are numerically equal only for a specific one-inch-thick volume convention, not for every product.
Should I use actual dimensions in a board-foot calculator?
Use actual dimensions for physical volume, but use the supplier’s stated tally dimensions when reproducing its bill.
What is the fastest way to compare lumber quotes?
Put both quotes on the same product specification and finished requirement, then include stock yield, milling, tax, and delivery rather than comparing unit price alone.
Choose the calculation behind this guide
- Board Foot Calculator
- Calculate board feet for rough lumber from thickness, width, length and board count, with a price-per-board-foot estimate.
- Linear Feet Calculator
- Add straight trim runs and repeated pieces into a linear-foot takeoff, then compare the total with stock length.
- Square Feet to Linear Feet Calculator
- Convert coverage area into linear feet using effective face width, overlap, waste allowance, and whole stock lengths.
- Lumber Cost Calculator
- Estimate lumber costs by whole stock boards, usable cut length, cutting allowance, tax, and a fixed delivery charge.
Read our editorial policy and calculation methodology. Product instructions and project-specific requirements take precedence over example allowances.