Log Scale Versus Weight: Estimating Value

The board footage (and the grade quality) produced from a ton of logs can vary widely, based on several factors. October 4, 2011

Here in the northwest we often buy logs by the ton, which makes things easier. I am looking for some info on what the board feet per ton recovery is on some of the local hardwoods (how many board feet in a ton of logs?). Bigleaf maple, alder, chinquapin, madrone.

Forum Responses
(Sawing and Drying Forum)
From contributor R:
This log volume chart will help you:

Log Volume

From contributor I:
When I was in logging, we used 12000 pounds for a thousand bd ft for pine and 15000 for hardwoods.

From Professor Gene Wengert, forum technical advisor:
The answer varies greatly with log diameter and species MC. Also, the value of the lumber obtained can vary by eight times easily, depending on log grade. So that is why weight scaling is seldom done with hardwoods. One approach is to assume 500 bf per cord and then go with standard numbers for the weight of a cord. Expect at least 50% variation with any method. Can you afford to spend 50% too much for logs or can the logger afford too little? The logger will take the best logs to another mill that will pay more, so you will not get high quality logs.

From contributor A:
We buy logs by the ton here in north central Arkansas most of the time. For hardwoods with 10" tops I have found that on my band mill I average about 250 bdft per ton of logs. The circle mills figure the cost at 200 bdft per ton. We then figure the cost per ton of logs on what the average of the logs would scale. For most loads the price right now is $36 per ton. Two years ago we were paying $45 a ton. Good SYP saw logs are paying $40 a ton and two years ago we were paying $50. ERC with 6 inch tops is going for $68 per ton.

Now if you get a load with some good butt cuts, you should make sure you throw a few Bens on top of the tonnage price and let the logger know why you are doing it.

From contributor W:
The best high production pine dimension mills have recoveries of around 4 tons/MBF. With hardwood cutting 4/4, it will not be as good, as there is more sawdust made and hardwood logs are generally a little more crooked!

On my little Wood-Mizer LT15, cutting 4/4 hardwood, I can expect somewhere around 5 weighed tons per actual green MBF of lumber. Size is key, so your recovery will be better with large logs and worse with small logs. Imagine one huge log that weighs 5 tons and compare that to a big pile of little 8" logs that weigh 5 tons and it is easy to visualize the difference in the waste factor.