CarpentryBoard Foot Calculator

Board Foot Calculator

Calculate board feet for lumber pricing and log scaling. Get instant cost estimates for hardwood purchases and sawmill logs.

Ready to calculate

Enter your lumber dimensions

Lumber Thickness Reference

QuarterRoughS2SCommon Uses
4/41"13/16"Cabinet sides, drawer fronts, small boxes
5/41-1/4"1-1/16"Deck boards, shelving, light furniture
6/41-1/2"1-5/16"Table tops, bench seats, thick shelves
8/42"1-13/16"Table legs, thick tops, workbenches
12/43"2-13/16"Turning blanks, mantels, heavy posts
16/44"3-13/16"Carving blocks, large turnings, timbers

S2S = Surfaced Two Sides

Rough lumber is planed on two faces, removing about 3/16" per side. Always buy based on the rough (quarter) size and plan for the S2S final dimension.

Expert Contributors

Why expert review matters

Every calculator is reviewed by certified professionals to ensure accuracy.Hawkin's CCP, CEP certification ensures professional-grade precision.

Pro Tips

  • Nominal thickness (4/4, 8/4) is rough-sawn size — S2S (surfaced two sides) removes about 3/16" from each face, so 4/4 rough becomes 13/16" finished
  • When buying hardwood, ask for random-width boards and pay by the board foot — you'll save 15-20% vs selecting specific widths
  • Always price lumber by the board foot, not by the piece. A 1" x 8" x 8ft board is 5.33 BF — at $8/BF that's $42.67, not whatever the tag says
  • Kiln-dried lumber (6-8% MC) costs more but won't shrink or warp. Air-dried (15-20% MC) is fine for rough construction but risky for furniture

Common Questions

What is a board foot?

A unit of volume for lumber: 1" thick x 12" wide x 12" long (144 cubic inches). It's the standard for pricing hardwood in the US.

How do you calculate board feet?

Thickness (in) x Width (in) x Length (in) / 144. For feet: T x W x L(ft) / 12. A 1" x 6" x 8ft board = 4.00 BF.

What is the Doyle log scale?

A formula estimating board feet in logs: BF = (D-4)^2 x L / 16. Common in the eastern US but underestimates small log yield.

How much does a board foot cost?

Pine $2-4, poplar $3-5, red oak $5-8, maple $6-10, cherry $7-12, walnut $10-18 per BF. Prices vary by grade and region.

What does 4/4 lumber mean?

4/4 = 1" thick rough-sawn. Each quarter = 1/4". So 8/4 = 2" thick. After surfacing (S2S), 4/4 finishes at 13/16".

Board feet vs linear feet?

Linear feet measures length only. Board feet measures volume (T x W x L / 144). A 2" x 6" x 1ft = 1 LF but 1 BF.

How the Calculator Works

1

Enter Dimensions

Input thickness, width, and length of your lumber. Use quarter-notation presets (4/4, 8/4) or enter a custom thickness. Toggle between feet and inches for length.

2

Calculate Board Feet

For lumber: BF = (T x W x L) / 144. For logs, choose Doyle, Scribner, or International 1/4" scale. Each formula estimates usable lumber from a round log differently.

3

Get Cost Estimate

Multiply total board feet by your price per BF. The calculator also estimates weight at 3.5 lbs per board foot (average hardwood density).

Key Formulas

Lumber: BF = (T" x W" x L") / 144

Doyle: BF = (D-4)^2 x L / 16

Scribner: BF = (0.79D^2 - 2D - 4) x L / 16

Int'l 1/4": BF = (0.905D^2 - 1.62D - 9.19) x L / 16

Species Price Guide

Approximate $/BF for 4/4 FAS grade

Pine (soft)
$2 - $4
Poplar
$3 - $5
Red Oak
$5 - $8
Hard Maple
$6 - $10
Cherry
$7 - $12
White Oak
$7 - $12
Ash
$5 - $9
Walnut
$10 - $18

Prices vary by region, grade, and supplier. Kiln-dried adds $1-3/BF.