Hardwood thickness in quarters
A quarter name is the rough thickness. Surfaced stock is thinner, and the tally still bills the rough size.
The quarter is the rough size
Hardwood thickness is named in quarters of an inch, and the name is the rough size before surfacing. 4/4 is 1 inch. 5/4 is 1 1/4 inches. 6/4 is 1 1/2 inches. 8/4 is 2 inches. Count the quarters: four quarters make an inch, eight quarters make two inches.
A planed board is thinner than that name. The 4/4 surfaced-two-sides preset on the board foot calculator uses 13/16 inch, which is a dressed thickness you can measure with calipers. The lumberyard tally still bills the rough 4/4. If you type 13/16 by hand while lumberyard tally is on, the page maps it back to 4/4 rough for the bill and keeps the exact board feet beside that tally.
Width and length
Face width is in inches. On a board that changes width, measure at one third of the length from the narrow end. Do not average the two ends. Length is in feet. One row on the calculator is one size; set the quantity on that row.
Nominal softwood such as a 2x4 keeps its name size. The dressed size, 1 1/2 by 3 1/2, undercounts the board feet a yard bills. Use the quarter names for hardwood, and the name size for that softwood.
Price the list on the board foot calculator. When you already have a board-foot total and need lineal feet, use board foot to linear foot. A log is a different measurement: the log scale estimates the board feet inside the log before it is sawn.
This guide explains the measurement the calculators use. It is not a permit review.
Use it on a calculator
FAQ
Is 4/4 the same as 1 inch?
Yes for rough stock. 4/4 is 1 inch, 5/4 is 1 1/4 inches, 6/4 is 1 1/2 inches, and 8/4 is 2 inches. Those names are the thickness before the board is planed. After surfacing, the same board is thinner than the quarter it was sawn from. Measure a planed board if you need the dressed thickness, and keep the quarter name for the bill.
Why does the tally ignore the planed thickness?
A lumberyard tally bills the rough thickness even when the board was planed. The 4/4 surfaced-two-sides preset uses 13/16 inch, which is the dressed thickness you can measure, and the tally still bills that board as 4/4 rough. Typing 13/16 by hand in lumberyard mode maps it the same way. The exact board feet stay on screen beside the tally.
How do I measure a board that tapers?
Record rough thickness in quarters, face width in inches, and length in feet. If the width tapers, measure it one third of the way from the narrow end and do not average the two ends. A nominal 2x4 is a different rule: enter the name size, 2 by 4 inches, because the dressed 1 1/2 by 3 1/2 undercounts the board feet a yard bills for softwood.
By Lumber Calc Editorial Team . The numbers follow the rules on the linked calculator pages. Last updated Oct 24, 2026.