Hardwood is sold by the board foot, a volume unit equal to 144 cubic inches. Softwood dimensional lumber is sold by the piece or linear foot. This calculator handles board foot volume, the quarter thickness system, and price comparison across both conventions.
Converting between board feet and running length? See Board Feet to Linear Feet.
About pricing on this page
This calculator is intentionally price-light. Absolute dollar figures are deliberately omitted because they vary too widely by region, brand, and installer to be useful as planning estimates. The relative-comparison tables below show how options stack up against each other — which is the durable, actionable information. For a real budget, get two or three written quotes from local suppliers and contractors after they have seen the job.
Board Foot Calculator
Enter board dimensions and quantity. Results give board feet and total cost.
The Board Foot Formula
Board Feet = (Thickness in × Width in × Length in) ÷ 144
or when length is in feet: BF = (Thickness in × Width in × Length ft) ÷ 12
One board foot is 144 cubic inches — the volume of a piece 1 inch thick, 12 inches wide, and 12 inches long. Because it is a volume measure, a 1 × 12 board eight feet long and a 2 × 6 board eight feet long both contain exactly 8 board feet.
Worked example: Six pieces of 4/4 walnut, 6 inches wide and 8 feet long. Each board is (1 × 6 × 8) ÷ 12 = 4 board feet. Six boards is 24 board feet. Add 15% for milling waste: 27.6 BF. At $12 per board foot for walnut that is $331.
The Quarter System for Hardwood Thickness
Hardwood thickness is quoted in quarters of an inch, referring to the rough sawn dimension before surfacing.
| Quarter Notation | Rough Thickness | Surfaced (S2S) | Typical Use |
|---|---|---|---|
| 4/4 (four quarter) | 1 in | 13/16 in | Cabinet doors, drawer fronts, panels |
| 5/4 (five quarter) | 1-1/4 in | 1-1/16 in | Stair treads, thick tabletops |
| 6/4 (six quarter) | 1-1/2 in | 1-5/16 in | Table aprons, chair rails |
| 8/4 (eight quarter) | 2 in | 1-3/4 in | Table legs, workbench tops |
| 10/4 (ten quarter) | 2-1/2 in | 2-1/4 in | Heavy legs, bench components |
| 12/4 (twelve quarter) | 3 in | 2-3/4 in | Turning blanks, thick legs |
| 16/4 (sixteen quarter) | 4 in | 3-3/4 in | Large turning stock, posts |
Board footage is calculated on the rough thickness you are charged for, not the finished surfaced dimension. Buying 4/4 lumber means paying for a full inch of thickness even though you receive 13/16 inch after surfacing.
Board Feet in Common Lumber Sizes
Nominal softwood sizes are larger than actual dimensions, but board footage is conventionally calculated on the nominal size.
| Nominal Size | Actual Size | BF per Linear Foot | BF in 8 ft | BF in 12 ft | BF in 16 ft |
|---|---|---|---|---|---|
| 1 × 4 | 3/4 × 3-1/2 in | 0.33 | 2.67 | 4.00 | 5.33 |
| 1 × 6 | 3/4 × 5-1/2 in | 0.50 | 4.00 | 6.00 | 8.00 |
| 1 × 8 | 3/4 × 7-1/4 in | 0.67 | 5.33 | 8.00 | 10.67 |
| 1 × 12 | 3/4 × 11-1/4 in | 1.00 | 8.00 | 12.00 | 16.00 |
| 2 × 4 | 1-1/2 × 3-1/2 in | 0.67 | 5.33 | 8.00 | 10.67 |
| 2 × 6 | 1-1/2 × 5-1/2 in | 1.00 | 8.00 | 12.00 | 16.00 |
| 2 × 8 | 1-1/2 × 7-1/4 in | 1.33 | 10.67 | 16.00 | 21.33 |
| 2 × 10 | 1-1/2 × 9-1/4 in | 1.67 | 13.33 | 20.00 | 26.67 |
| 2 × 12 | 1-1/2 × 11-1/4 in | 2.00 | 16.00 | 24.00 | 32.00 |
| 4 × 4 | 3-1/2 × 3-1/2 in | 1.33 | 10.67 | 16.00 | 21.33 |
| 6 × 6 | 5-1/2 × 5-1/2 in | 3.00 | 24.00 | 36.00 | 48.00 |
Hardwood Price per Board Foot
Rough 4/4 lumber, kiln dried, FAS grade, 2026 retail. Prices swing widely by region and supplier.
| Species | Price per BF | Hardness (Janka) | Common Use |
|---|---|---|---|
| Poplar | Reference only | 540 | Paint-grade trim, secondary wood |
| Soft maple | Reference only | 950 | Cabinets, furniture, paint grade |
| Red oak | $4.50–$7 | 1,290 | Furniture, flooring, trim |
| White oak | Reference only | 1,360 | Furniture, boats, exterior |
| Hard maple | Reference only | 1,450 | Butcher block, cabinets, floors |
| Cherry | Reference only | 950 | Fine furniture, cabinetry |
| Walnut | Reference only | 1,010 | High-end furniture, accents |
| Mahogany (genuine) | Reference only | 800 | Boats, fine furniture, doors |
| White ash | $4.50–$7 | 1,320 | Tool handles, furniture |
| Hickory | Reference only | 1,820 | Flooring, tool handles, cabinets |
Wider boards command a premium — a 12-inch-wide walnut board costs more per board foot than a 6-inch board of the same species and grade, because wide clear stock is scarcer.
Common Board Foot Mistakes
Dividing by 144 When Length Is in Feet
The divisor depends on your length unit. Use 144 when all three dimensions are in inches, and 12 when length is in feet while thickness and width are in inches. Mixing these produces an answer off by a factor of twelve. Since lumber is almost always quoted with length in feet, the divisor you want is usually 12.
Calculating on Surfaced Rather Than Rough Thickness
A 4/4 board arrives at 13/16 inch after surfacing but is sold as a full inch of thickness. Calculating board footage on 13/16 understates the volume by about 19%, which means your cost estimate comes in low and your material order comes up short. Always calculate on the quarter designation you are being charged for.
Skipping the Waste Allowance on Rough Lumber
Rough sawn hardwood contains checks, wane, knots, and cupping that all have to be milled away. Fifteen percent is the minimum realistic allowance for straight-line ripping and jointing to usable stock, and 30% is common on lower grades or when you need specific clear widths. Furniture makers routinely buy 40% over their cut list.
Comparing Board Foot Prices to Linear Foot Prices
A quote of $6 per board foot and a quote of $6 per linear foot are not comparable without knowing the board dimensions. A 1 × 12 board contains 1 board foot per linear foot, so the two prices match. A 1 × 6 contains only 0.5 board feet per linear foot, so $6 per board foot is really $3 per linear foot. Always convert to a common unit before comparing.
About these price ranges
Pricing varies widely by region, season, project size, and site conditions. Treat every figure on this page as a planning estimate for budgeting only — not as a quote. Coastal metro markets commonly run 20–40% above national ranges while rural inland markets can fall 10–20% below. Always collect at least three written quotes from local contractors before committing to a budget.
Unsourced estimates: All dollar figures on this page. The relative-comparison tables above are sourced from general trade conventions and the labour-plus-material methodology used in industry references, not from a specific published price index. These are informed planning figures rather than data drawn from a published price index, and they carry a correspondingly wider margin of error.