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Converting lineal ft cost to board foot cost10/10
Is there a formula to convert a lineal foot cost to board foot cost? If I have an S4S 5/4 board that is 2.125" wide that I paid $.85/lf for, how much did I pay per board foot? Any help with this would be greatly appreciated.
You paid $4.80 /sf, and approximately $3.84 /bdft. Board ft is usually figured before shrinkage or machining though, so it's pretty useless to figure it backwards from actual dimensions.
BF= 2.125x12x1.25 =0.221354167 BF
.85/.221354167=$3.84 per BF
For pieces that are narrower than 4", we seldom figure the BF, as it is rather meaningless. Instead we use lineal footage or a piece count. That is just the tradition, like it or not.
Is this hardwood? If so, then right now, after drying an planing, the footage for a piece 1' long is
Then, area x thickness is BF. so 0.177 x (5/4) = 0.22 BF (or about 1/4 BF).
[Note that in Alan's posting, there is a typo...
For a softwood, we use the nominal size, rather than the actual size when calculating BF. That is why a 1-1/2" x 3-1/2" piece is called a 2x4. So, it is really not possible to calculate the softwood footage because we do not know the nomad width. Should we consider this a 1x3 piece? Normally, a softwood 1 x 3 is actually (after drying and planing) 1-1/2" x 2-1/2", so your piece is a bit smaller. So, a softwood BF is very confusing. That is why BF is not used, but lf or piece counts, as mentioned before.
As a side note, if you want to figure your cost per Lft to produce the part out of random width hardwood lumber you can use the same formula with a twist. You have to know your yield at the ripsaw and the cost per bf for the lumber. Add those to the previous formula and you know how much the part costs to make. If you think the yield is going to be 68% for instance, then the formula will be: