So I took a gander at a high-end wood retailer today at lunch and came
across some stuff that I can't figure out. Some boards were sold as $x.yy
per board foot and others were sold as $x.yy per square foot. Why the
differences? It appeared as though the 1/2 boards were all sold square foot
and the 4/4, 8/4, and 16/4 boards were sold board foot. What exactly is a
board foot? I'm presuming that's what BF meant on the price - and none of
the wood was dimensioned.
A board foot of 4/4 wood is 12 x 12 inches. A board foot of 8/4 wood is 6x6
Boards thinner than 4/4 are usually sold by the square foot if for no other
reason that people
don't realize how much it costs. To make a 1/2 inch thick board, people
usually start with
4/4 and plane it down. The customer pays for the scrap.
Boards sold by the board foot need not be otherwise dimensioned.
And, hardwood is sold in random widths and random lengths. You pay plenty
for the scap if you want
specific widths and / or lengths.
Jim was typing faster than he was thinking. 12 x 12 x 1 is a board foot
So is 6 x 12 x 2 a board foot. It is probably easier to think in terms of
144 cubic inches. Keep in mind, a board that is sitting on the shelf that
measures 12 x 12 x 3/4 was planed down so it will still be charged as a
Just to confuse you more, some of the big box stores sell their wood by the
lineal foot. That way, a 6" wide board will cost roughly double per foot
compared to a 3" wide board.
And then there's places that price by the POUND!
I was comparing pricing cocobolo and jarrah for a clients goblets and the CB was
available in 4" x 4" x 12" pieces for $40..
Ok, that's the kind of stuff I can understand... Maybe even calling it 16/16 or
OTOH, the jarrah was $6 a pound???
I emailed them asking what the approximate weight of a 4x4x12" chunk of jarrah
was and got "about 8 or 10 pounds" as a reply.. hard to give a client a bid
based on that pricing..lol
Please remove splinters before emailing
A board foot is a VOLUME of 144 cubic inches of ROUGH wood. Picture a
1' by 1' by 1" slab of rough cut wood; that's a board foot. In fact,
go make one, write "BF" on it, and hang it in your shop. Make a
2"x6"x12" one to go next to it, and a 1"x6"x24" one too. They're all
a board foot.
A 1 foot cube of wood (1x1x1) is thus 12 board feet.
Some things are easier to sell by the linear foot, like mouldings.
Some things are easier to sell by the square foot, like plywood.
With surfaced wood, you have to figure it based on the original rough
size. Thus, a 1.5 x 3.5 x 8' board is 2 x 4 x (8*12) / 144 = 5.33 bf.
What I tend to do is figure out how long a board has to be to be a
board foot, then scale. Example: a 2x8 rough is 16 sq in, or 4/3 of a
sq ft. So a board foot is 3/4 of a foot of that board, or a 2x8 9"
long. A 9 foot length is thus 12bf.
A 2x6 or 1x12 is 1 bf per foot of length.
A 1x6 or 2x3 is 1 bf per two feet of length.
A 1x4 is 1 bf per 3 feet of length.
BF is LxWxH in inches divided by 144. Hardwood is often sold in the
quarters system where 4/4=1" thick, 6/4= 1.5" thick, etc...
So as an example, a 4/4 board that measures 6" wide and 72" long would be:
1" (H) X 6" (W) X 72" = 432 cubic inches/144 cubic inches = 3BF.
What makes sense is to use the built-in terminology and screw the 144
My pickup has 4 ft of 102" (8ft) boards per tier. Makes 32 my base. 4/4 is
the 32, 5/4 is 160(5x32)/4 = 40 . That way you can do your calcs in your
head if you're over forty, with a pencil if you're over thirty, or trust the
pimple-factory and his calculator if you're younger ....
I use a slight variation of the calculation -- for me it is easier to do in
my head while shopping for the lumber I want or need.
A x B x C
Where A = thickness in inches B = width in inches C = length in feet
So for example I have a 4/4 piece of oak that is 6" wide and 8 feet long.
1 x 6 x 8
--------- = 4BF
Yeah, that's the way I learned it, from some book in the distant past...
Wouldn't it work out the same if you used an inch per foot on the length and
didn't have to divide the sum by 12?
(Yeah, I flunked math in HS)
Please remove splinters before emailing
Yeah, there are all sorts of ways to figure it given there are feet and
inches involved. I personally found a tape measure that had
the BF scale on the back of it similar to what the lumber yard uses to
measure BF and use that although for a board or two, I usually just
do it in my head.
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