how much wood per tree length

was wondering,how may logs at 15 ft. long and 12 inches in dia.would it take to have a cord of wood4X4X8.

er. 9ish by my new math

8.5

All correct.

I guess I'm coming up with a little different answer:

pi x radius^2 x length = cubic feet of wood per log

for a 15 foot x 1 foot log:

3.14 x .5 ft ^2 x 15 = 11.77 cubic foot of solid wood per log

http://firewoodresource.com/articles/cord.html

So:

Max = 90 cu ft / 11.77 = 7.6 logs

Avg = 80 cu ft / 11.77 = 6.8 logs

Min = 70 cu ft / 11.77 = 5.9 logs

There is no airspace in the log.

I calculated how many of those logs it would take to make 1,000 board feet and cut the number in half, since there are generally thought to be about two cords per MBF. That's a very rough measurement (different log scales yield different BF totals for the same logs), but I came up with 8.5. So it's somewhere between 8 and 9 logs, by that measure.

And it's going to shrink as it dries. Some people thing that's a negligible factor, but if you have a good pile of wood--say 10 or 20 cords, you could easily lose the better part of a cord as it dries. That's one thing people don't realize about the firewood business--dry wood costs more not only because somebody sat on it long enough for it to dry, but they wind up with less wood than they started with, and have to add more to make it come out to a full cord for the customer.

I figured out how much at one point, but the thread was lost on the old forum (before we got this fancy software) and it's gone. I stack my wood 6.5 feet high, and I think a green stack shrunk down to something like 6' over the course of the summer and fall. So that would be 7.6%. Nothing to sneeze at. That's 3/4 of a cord lost for every 10.

I work with a lady who had a dog once that would steal wood from the neighbor's pile and bring it home. I think they trained him to do that, though they deny it. So losses are not always limited to drying.

Another friend had a dog that would run in front of you and break trail on backcountry skiing trips. It was great for the most part, except that sking around in those tight little circles periodically would get a little old. That and chasing rabbits.

Ja, I stack my wood 9 feet tall in my woodshed and I've seen that phenomenon when I stacked very green wood rows right tight together. As the face row shrank, the edges would catch on the previous row and also the exposed face dried and shrank at a faster rate than the backside causing the face of the last row to curl away and topple.

I stack right tight to the rafters and have seen as much as a 9 inch gap form as it shrank. Given the height of 9 feet, that is about one inch per foot so 1/12th or 1 cord lost in 12 cord to shrinkage. I don't usually stack green wood in the shed, preferring to leave it loose piled out in the sun and wind for a few months first. Here are a couple of pics of wood that sat out first. There is less than 4 inches of gap.

Thanks, guys. Now I don't feel so bad about that stack of maple that is sagging against the neighbor's fence!

A good source of info for log scaling :http://www.for.gov.bc.ca/hva/manuals/scaling/pdf/Ch4.pdf

cozy heat has the right answer at 11.77 cu./ft. per log

I put a spreadsheet together for buying logs using Smalian's log scaling formula

Using a different method: My woodlot tables shows one log would be .145 cord or 6.9 trees for a cord.

Actually, the estimate was 6.9 logs. The real answer is 6.896552. :coolsmile: