I sometimes get asked what the difference is between the amount of wood in a cord of split vs unsplit wood, or larger vs smaller split pieces. Or how to measure a cord of wood that is not split. The answer to the last question is, it gets measured the same. If it is not split, you can stack the cut but unsplit pieces, or rounds, and measure them like any other cord. But the interesting thing is, I have noticed some difference in volume between the two.
I have noticed this difference in volume when I sometimes haul firewood that is cut into rounds from the woods to the splitter. Rounds are the pieces that are cut but not yet split. In some cases, if the rounds are too big to handle, I will rip them into halves, quarters or pieces that are small enough to handle. Either way I call them rounds.
If I stack the rounds in my trailer, I can fit a full cord into it. If I take that cord of rounds and run it through the splitter, then stack the split pieces back in the trailer, I always have wood left over when the trailer is filled up to the same level that the rounds were. So there is obviously more solid wood in a cord of large pieces, than a cord of small pieces.
The reason for this is, when the pieces are split smaller, there will be more pieces in a cord. With more pieces, there will be more air spaces between the wood. With larger pieces, the spaces may be larger, but in this case, many of the smaller spaces take up more space than the fewer larger spaces. And this is always the case regardless of whether the unsplit pieces are round quartered or cut into halves. I would say it is even more so when the pieces have flat edges.
So what does this mean? If you buy wood that is split smaller, you will get less actual wood per cord. But it’s not that big a difference. So if you like the smaller pieces, I wouldn’t go to larger pieces just because of this. I would say go ahead with the size you prefer. In a lot of cases, with some stoves, burning smaller pieces can produce a cleaner more efficient burn. In this case, you will probably still come out ahead with smaller pieces.
How much is the difference in volume? This all depends on the size of the rounds and the size of the split wood. Also how tightly it is stacked. I have not really kept track of it or measured the left overs. But I would say it’s small enough not to worry about it.