Hardwood tally calculator

The tally follows the NHLA rules — surface measure rounded board by board, lengths dropped to the whole foot — and shows how that compares with your own math. For one board or construction lumber, the board foot calculator is simpler. New to this? Words explained.

How a hardwood yard tallies a stack

Hardwood comes in random widths and lengths, so the yard measures every board. Under the National Hardwood Lumber Association (NHLA) rules the unit is surface measure (SM): the board’s face area in square feet, rounded to a whole number. Board feet are then the surface measure times the thickness in inches.

surface measure = width (in) × length (whole ft) ÷ 12, rounded to a whole number
board feet = surface measure × thickness (in)   — stock under 1 in counts as 1 in

• Length drops to the whole foot. A board 8 ft 6 in long is tallied at 8 ft. Standard lengths run 4 to 16 ft in whole feet, and the extra inches come free.
• Surface measure rounds to the nearest whole foot. Below one half is dropped, above one half goes up, and exactly one half is rounded up and down alternately from board to board.
• Thickness multiplies the whole pile. 4/4 counts as 1, 5/4 as 1¼, 8/4 as 2. Stock thinner than 1 in is counted as if it were 1 in, so its board feet equal its surface measure.
• Tapered boards are measured a third of the way along from the narrow end.

The starting boards in the calculator show all of it. The 7¼ in × 8 ft 6 in board is tallied at 8 ft: 7¼ × 8 ÷ 12 = 4.83, which rounds to 5. The 6 in × 9 ft board is exactly 4½ and rounds up; the 9½ in × 12 ft board is exactly 9½ and, as the next half, rounds down to 9. The 5 in × 10 ft 3 in board is tallied at 10 ft: 4.17 rounds to 4. The four come to 23 surface measure, which at 4/4 is 23 board feet — about 0.41 less than the 23.41 you get by multiplying every inch.

Why your math and the receipt differ

Measuring each board to the inch and multiplying gives a slightly different total from the yard’s tally, for three reasons: fractional feet of length are dropped, each board’s surface measure is rounded, and thin stock is counted as a full inch. Rounding goes both ways and tends to even out over a big pile; dropped length always works in the buyer’s favour on the wood you carry home, because you get the overlength without paying for it.

The AHEC grading guide works one example: a board 2 in thick, 6¼ in wide and 8 ft long is 4⅙ square feet, tallied as 4 surface measure and 8 board feet. Enter 6 1/4 and 8 at 8/4 above and you get the same 8.

More than one thickness

Each tally here is one thickness, because the thickness multiplies the whole stack and thicker stock is usually priced higher per board foot. For a mixed order, tally the 4/4, then add it to your project list, switch to 8/4 and tally those boards — the project list keeps a board-foot total for each thickness, and the cost lines add up across them.

Tips at the yard

• Measure the width across the face of each board; for a tapered board, measure a third of the way along from the narrow end, as the NHLA rules do.
• Round nothing yourself — type widths to the nearest 1/4 in (7 1/4) and lengths in feet and inches (8' 6"). The calculator does the yard’s rounding.
• Several boards the same size? Enter the width and length once and set Qty — each board is still tallied on its own, so halves keep alternating.
• Surfaced boards are still tallied on their rough thickness, measured before surfacing.
• Add 20–30% waste for a project when you work out how many board feet you need; the tally only tells you what you are paying for.

For a single board, a bundle quote or softwood, use the board foot calculator — board feet in a 4/4 hardwood board, 8 in × 8 ft walks through one — and 100 board feet of 4/4 × 6 in in linear feet turns an order into running length. The hardwood buying guide covers grades and surfacing.