Cord of wood

lunkerslayer

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Been trying to figure out the best way to calculate how many cords are in unspilt logs, i know a cord is 4x4x8 which is 128ft3, which depending on how you split the wood it will also have air volume in that 128. So is there an easier solution to figuing out how much wood is in log thats 1 foot by 9 feet which is pretty much the same from one end to the other. I read on another forum where a poster figured that 90ft3 would be better because you are deducting the air volume from the original 128ft3.
 


KDM

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Figure out the volume of a cylinder (your log) and go from there. You should be able to get pretty close assuming the radius of each end of your log are similar. I hate math.
 

Allen

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Mathematically, this doesn't sound that difficult, if I understand the question.

If your logs are uniformly 1 ft in diameter x 9 ft in length, it goes like this.

1 ft diameter by 9 ft length log would exactly fit in a 1 ft by 1 ft by 9 ft box (interior measurements). That means a box of 9 cubic ft would hold one log.

The log's volume is equal to pi x r^2 x length. In your case, pi which is roughly 3.14159..., times 0.5^2 which equals 0.25 sqft, times 9 ft = 7.0685 cubic feet.

9 cubic feet minus 7.0685 cubic feet = 1.9315 cubic feet is how much air you would be selling with a single log.


Do with the above info as you wish.
 

riverview

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So you're asking for the difference between unsplit and split wood? your split wood will give you 1/4 more wood when piled split
 


snow2

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Well at my place I don't care or need brain damage stack rat hole cut logs from new ski trails (free) 5' length always have 3cords split and stacked and enough backup logs to heat for a couple years if needed as wood burner is 80% of my winter heat source at my mtn place in co. always have left over come spring
 

johnr

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I believe a pickup box is about a cord, is there some fancy sales happening where you need to skim a log or two for the profit margin?
 


lunkerslayer

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No the guy has logs cut to 9 foot lenghts wanted to see if there is a unsplit amount for a cord of wood.
 

Davy Crockett

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This sounds like a good job for AI...

AI Isn't sure either.

There seems to be some debate and confusion about whether a cord of unsplit wood (rounds) or a cord of split wood yields more actual wood volume. Here's a summary of the arguments:
Less air space: Unsplit rounds, when stacked, naturally minimize the air gaps between them because of their round shape, according to one source.

Splitting introduces voids: When rounds are split, it introduces more air space when the pieces are stacked, potentially leading to a larger overall volume for the same amount of actual wood, says one contributor.
  • Tighter stacking: Some argue that split wood, particularly when stacked carefully, can be packed more tightly than rounds, reducing the air spaces and potentially resulting in more actual wood per cord.
  • Less bark: Splitting exposes more wood and reduces the amount of bark, which has a lower density than the inner wood, potentially contributing to a denser and more fuel-efficient stack

Practical experience: Some users note that when they split a stack of rounds, the resulting volume of split wood ends up being smaller than the original stack.








Conclusion
The debate highlights the difficulty in precisely measuring the actual wood content in a cord, especially with varying shapes and stacking techniques. While a cord is a standard volume measurement, the amount of solid wood within that volume can vary depending on whether it's split or unsplit and how tightly it's stacked.
 

Maddog

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Somewhat off topic:

According to the Poetry Foundation, a woodchuck would chuck “As much wood as a woodchuck could chuck, If a woodchuck could chuck wood.” (bit.ly/woodchuck-poem) Researchers at Cornell determined that a woodchuck could chuck about 700 pounds.


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  • The 700-Pound Answer: The most widely cited hypothetical answer suggests a woodchuck could chuck about 700 pounds of wood, based on the amount of dirt it moves when digging its burrow.
 


Davy Crockett

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That made me wonder how much wood can a beaver chuck .

That's a classic tongue-twister, originally about woodchucks! Beavers are known for their ability to cut down and move wood for building dams and lodges, not exactly "chucking" it in the way a person might throw something.
While there's no exact scientific measurement for how much wood a beaver could chuck, research shows they're incredibly efficient. Beavers use their strong teeth and jaw muscles to cut down trees and transport branches to build their homes and dams. They primarily eat the soft inner bark (cambium) of trees, leaving the woody parts to be used for construction. They have been observed toppling trees up to 33 inches in diameter, according to Quora.
They can fell a medium-sized tree in a single night. A single beaver can also remove nearly 150 chips of wood from a 5-inch diameter tree in about 8 minutes. They are capable of clearing several acres of trees over a year. So, while they don't exactly "chuck" it, they can certainly process and transport a significant amount of wood!
 

Lycanthrope

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AI Isn't sure either.

There seems to be some debate and confusion about whether a cord of unsplit wood (rounds) or a cord of split wood yields more actual wood volume. Here's a summary of the arguments:
Less air space: Unsplit rounds, when stacked, naturally minimize the air gaps between them because of their round shape, according to one source.

Splitting introduces voids: When rounds are split, it introduces more air space when the pieces are stacked, potentially leading to a larger overall volume for the same amount of actual wood, says one contributor.
  • Tighter stacking: Some argue that split wood, particularly when stacked carefully, can be packed more tightly than rounds, reducing the air spaces and potentially resulting in more actual wood per cord.
  • Less bark: Splitting exposes more wood and reduces the amount of bark, which has a lower density than the inner wood, potentially contributing to a denser and more fuel-efficient stack

Practical experience: Some users note that when they split a stack of rounds, the resulting volume of split wood ends up being smaller than the original stack.








Conclusion
The debate highlights the difficulty in precisely measuring the actual wood content in a cord, especially with varying shapes and stacking techniques. While a cord is a standard volume measurement, the amount of solid wood within that volume can vary depending on whether it's split or unsplit and how tightly it's stacked.
Heres Grok 4 answer:

A standard cord of firewood is defined as a stack measuring 4 feet high by 4 feet deep by 8 feet long, totaling 128 cubic feet. However, this volume includes air space between the pieces when the wood is split and stacked. The actual solid wood content in a cord typically ranges from 80 to 90 cubic feet, depending on factors like the wood species, how finely it's split, the piece sizes, stacking tightness, and moisture content (drier wood may settle more). A common consensus from forestry resources is around 85 cubic feet of solid wood per cord, meaning about 33% air space.


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Your forum poster's suggestion of 90 cubic feet aligns closely with the upper end of this range and accounts for less air space in well-stacked, larger-split wood.For unsplit logs, the key is to calculate the solid volume of the log first (since it's essentially 100% wood with no air gaps yet), then divide by the solid wood volume per cord to estimate how many cords it would yield once split and stacked. This approach deducts the eventual air space implicitly.Step-by-Step Calculation for Your Log (1 Foot Diameter by 9 Feet Long)Assuming the log is cylindrical (as it's "pretty much the same from one end to the other") and the "1 foot" refers to the diameter:
  1. Convert dimensions: Diameter = 1 foot (12 inches), so radius = 0.5 feet. Length = 9 feet.
  2. Calculate solid volume: Use the cylinder volume formula,
    V=πr2hV = \pi r^2 hV = \pi r^2 h
    , where ( r ) is the radius and ( h ) is the length.
    V=π×(0.5)2×9=π×0.25×9=2.25π≈7.07V = \pi \times (0.5)^2 \times 9 = \pi \times 0.25 \times 9 = 2.25\pi \approx 7.07V = \pi \times (0.5)^2 \times 9 = \pi \times 0.25 \times 9 = 2.25\pi \approx 7.07
    cubic feet.
    (If the ends differ slightly, measure diameters at both ends, average the cross-sectional areas, then multiply by length for a more precise volume.)
  3. Estimate equivalent cords: Divide the log's solid volume by the solid wood per cord.
    • Using 90 cubic feet solid per cord (per your forum example):
      7.07/90≈0.0797.07 / 90 \approx 0.0797.07 / 90 \approx 0.079
      cords (about 1/13 of a cord).
    • Using 85 cubic feet solid per cord (common consensus):
      7.07/85≈0.0837.07 / 85 \approx 0.0837.07 / 85 \approx 0.083
      cords (about 1/12 of a cord).
This is the easier solution you're seeking: Measure the log's solid volume, then adjust for the air space by dividing by 80–90 instead of 128. If you have a pile of multiple logs, sum their individual volumes first, then divide similarly. For more accuracy:
  • Account for bark or taper if significant (subtract ~10-15% for thick bark).
  • Use a log volume app or table (e.g., International 1/4-inch rule for firewood estimates, though it's more for lumber).
  • Test-split a sample log and measure the stacked volume to calibrate your solid-per-cord figure for your specific wood and splitting style.
If your log dimensions are different (e.g., if "1 foot by 9 feet" means something else like height/width for a non-round log), or if you provide details on the wood type/multiple logs, I can refine the calculation!
 

lunkerslayer

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Thats what i read on another forum that 90ft3 was the consensus for unsplit to a cord. 128:90 split to unspilt
Also this is all hardwood oak and ash
 


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