Estimating Cords of Wood

[johnpma]

For those who cut your own wood do you have any tricks to estimate how much wood you would get per tree?? My property has some down oak, birch, and maple from storms two years ago. Looking at all of this I'm trying in my mind to figure out how many cord are there

Any quick tips for estimates??

 

[gzecc]

One cord per average size mature tree.

 

[paul bunion]

For a rough guess you can mentally stack the logs in 8' lengths as if they were splits and compute the volume.

To start measure the length of a log and average it's diameter. Then stack them up in 8' lengths into a pile that is 4 feet high and wide. So say you have a log that is 32 feet long and runs about 24" in diameter. Cut it into four 8 foot lengths, stack it 2 wide and 2 high to get 4 feet. You are working on having a cord. If you have logs that run about 16" you will need to make a stack that is three logs wide and high. Crowns on forest trees generally do not yield much so you can discount them entirely from your estimate figuring that they will just fill in the gaps. If they are a yard or field tree they can give you some measurable wood, but the log is where most of the meat will be.

 

[tsquini]

Define the cubic feet of the log. This is the equation: V = pi × radius↑(2)× height
This is how it is done: Lets say you have a 3' diameter log 20' in length. You want to do it is feet for figure out the a cord volume(128sqft). This equation does not take account for the taper of the trunk. If you measure the radius of the narrow end will end up with a little more wood than calculated.

radius↑(2): 1.5↑(2) = 2.25

volume of a one foot section: 2.25 * 3.14 = 7.065

Factor is the length: 7.065 * 20 = 141.3

The total square feet volume of the log is: 141.3' = 1.103 cords

 

[Ashful]

One cord per average size mature tree.

Your average trees must be incredibly small. I average 3 - 6 cords per tree.

Figure 85 cubic feet of wood per stacked cord (US weights & measures estimate). A stubby 50' trunk with diameter 36" at mid-height will yield 4.2 cords, and that's before you even tackle any of the branch wood. A 3-cord tree might have a 2-cord trunk (28" avg.dia. x 40' long) and 1 cord in branch wood.

The total square feet volume of the log is: 141.3' = 1.103 cords

Again, it's not possible to stack at a density of 128 cu.ft. of wood per cord. At a more typical 85 cubic feet of wood per 128 cu.ft. cord, you actually have 141 cu.ft. = 1.7 cords.

 

[paul bunion]

Define the cubic feet of the log. This is the equation: V = pi × radius↑(2)× height
This is how it is done: Lets say you have a 3' diameter log 20' in length. You want to do it is feet for figure out the a cord volume(128sqft). This equation does not take account for the taper of the trunk. If you measure the radius of the narrow end will end up with a little more wood than calculated.

radius↑(2): 1.5↑(2) = 2.25

volume of a one foot section: 2.25 * 3.14 = 7.065

Factor is the length: 7.065 * 20 = 141.3

The total square feet volume of the log is: 141.3' = 1.103 cords

You are computing solid volume without airspace. You need to add in some air space in your stack. The way I suggest, which essentially treats the round log end as a square, underhandedly factors the airspace in.

 

[gzecc]

OP was looking for a quick tip on already down trees. Not multiple equations.
If you factor rot, termites, ants, punk, I think 1 cord per tree is a good average.

 

[Ashful]

It all depends on where you live, and what you're cutting. Around here, I don't see many trees that small falling in storms, as they're usually young and healthy. What came down around here in Sandy was mostly the big old 4+ cord monsters, due to age, rot, sheer size, etc. Most of the smaller 1 cord trees that fell were those wiped out by a bigger tree falling on them.

 

[Applesister]

You guys must have big trees in Philadelphia. Monster big. lol. trees Im talking about!!

 

[Ashful]

I suspect Philly is similar to any other old mid-Atlantic city (Baltimore thru Boston). However, I'm in rural / suburban land, 30 miles northwest of center city. Mostly farms established late 1700's / early 1800's, since either preserved or converted to development. The old hedgerows and "unimproved" spaces have a lot of big old trees, and this is mostly what saw falling during the last few unusual storms. There are surely more young trees, by count... but these don't seem to be the ones falling when the wind blows.

 

[Backwoods Savage]

We just keep cutting until we have enough then stop. Never have been concerned about how much we'll get from any one tree.

 

[tsquini]

You are computing solid volume without airspace. You need to add in some air space in your stack. The way I suggest, which essentially treats the round log end as a square, underhandedly factors the airspace in.

Yes, I am computing solid volume of a round cylinder. Which is inherently incorrect because a tree trunk is not a perfectly round cylinder and the wood is green with roughly 50% water content. As the wood dries it decreases volume, making the long-term accuracy of the results incorrect.So,There are a lot of flaws in the equation for this particular application. But if we go back to the original question "estimate how much wood you would get per tree". You can get a rough idea of volume of a tree based on the equation. If you want to figure out the volume of the limbs you can. Unfortunately, the same flaws apply.

 

[STIHLY DAN]

I believe its a 22" diameter tree yields 1 cord 11" = 1/3 cord.

 

[red oak]

After cutting wood for 13 years, I still am awful at predicting how much I'll get from a single tree. Like not even close. So I have to saw it into rounds and then load it onto my truck, if I'm away from home. A load on my Ranger is about a quarter of a cord, maybe a third if it's stacked high. If the tree is on my property when it's split and stacked I can measure.

 

[Gboutdoors]

Here you go this should help.


http://ucanr.edu/sites/placernevadasmallfarms/files/76320.pdf

 

[jatoxico]

Here you go this should help.


http://ucanr.edu/sites/placernevadasmallfarms/files/76320.pdf

I like that, should go in the sticky.

 

[tsquini]

Here you go this should help.


http://ucanr.edu/sites/placernevadasmallfarms/files/76320.pdf

This is good. I never thought of estimating volume by acre.

 

[STIHLY DAN]

Here you go this should help.


http://ucanr.edu/sites/placernevadasmallfarms/files/76320.pdf

Yes I was right! Thanks for the proof. I got the info from the same place but different section.

 

[Wood Duck]

I'd cut and split the birch first. It will rot a lot faster than oak and maple.