Frame Sums

Reference chart

Board Foot Chart & Calculator

Board feet for every common nominal size at the lengths the yard stocks. Read the row for your size and the column for your length; multiply by the piece count. The calculator below handles hardwood quarters, odd lengths and a price.

Board feet by nominal size and length

Board feet per piece, nominal dimensions. bf = T × W × L ÷ 12.
Sizebf per ft6 ft8 ft10 ft12 ft14 ft16 ft20 ft
1x20.1671.001.331.672.002.332.673.33
1x30.2501.502.002.503.003.504.005.00
1x40.3332.002.673.334.004.675.336.67
1x60.5003.004.005.006.007.008.0010.00
1x80.6674.005.336.678.009.3310.6713.33
1x100.8335.006.678.3310.0011.6713.3316.67
1x121.0006.008.0010.0012.0014.0016.0020.00
2x20.3332.002.673.334.004.675.336.67
2x40.6674.005.336.678.009.3310.6713.33
2x61.0006.008.0010.0012.0014.0016.0020.00
2x81.3338.0010.6713.3316.0018.6721.3326.67
2x101.66710.0013.3316.6720.0023.3326.6733.33
2x122.00012.0016.0020.0024.0028.0032.0040.00
4x41.3338.0010.6713.3316.0018.6721.3326.67
4x62.00012.0016.0020.0024.0028.0032.0040.00
6x63.00018.0024.0030.0036.0042.0048.0060.00

Your numbers

Board feet

53.33

5.333 bf each

Per piece

2 × 4 × 8′

5.333 bf

Cost

enter a price per board foot

bf = T × W × L(in) ÷ 144 = 2 × 4 × 96 ÷ 144 = 5.333 per piece.

Questions

How do you calculate board feet?

Thickness in inches × width in inches × length in feet ÷ 12, all on nominal sizes. A 2×4×8 is 2 × 4 × 8 ÷ 12 = 5⅓ board feet. In inches throughout, divide by 144 instead. A board foot is a 12 × 12 × 1 inch block of wood, 144 cubic inches.

Nominal or actual size?

Nominal. A 2×4 is 1½ × 3½ actual, but board feet are figured on the 2 × 4 it was sawn as, which is why the chart matches what the yard charges. Hardwood dealers use quarters for thickness: 4/4 is 1 inch, 8/4 is 2 inches, and rough width is measured to the nearest inch.

How many board feet in a 2×4×8, 2×6×8 and 2×12×16?

5.33, 8 and 32. Read across the chart: the 2×4 row at 8 feet, the 2×6 row at 8 feet, the 2×12 row at 16 feet.

How do I price a lumber list by board feet?

Multiply the board feet by the price per board foot; the calculator does it when you enter a price. Framing lumber is usually sold by the piece, hardwood and rough-sawn stock by the board foot, and the chart converts either way.

What about linear feet and square feet?

Linear feet ignore width and thickness, so 100 linear feet of 2×4 is 66.7 board feet but 100 linear feet of 2×12 is 200. Square feet of one-inch stock equal board feet; for other thicknesses multiply the square footage by the nominal thickness.

Charts are computed from the formulas and code figures stated on the page (International Residential Code limits where cited). They are planning and take-off numbers, not engineering: species, grade, span tables and local amendments govern anything structural. Confirm with your inspector before you cut.

All charts