I would think that firewood estimator would vary depending on area due to differing species. I'm thinking an oak would have a larger crown (lots more big branches useable for firewood) than say a Loblolly ( no I don't use the pine for firewood). But on an average it might be close.
As already noted in my original post: "This varies a bit with species and site conditions, and I'm sure would vary a bit with different regions of the country." Different regions and different sites do tend to have different form factors.
Around here, "firewood" means "hardwood". No one harvests softwoods for firewood unless they have no choice (well, with the exception of those folks who are determined to give outdoor wood boilers a bad name by burning anything from their kids' dirty diapers to freshly cut White Pine to the wet, half rotten mess they scrounged from a neighbor's 5 year old storm damage). So I have no experience applying that table to softwoods. We're cutting Red Oak, White Oak, Beech, Hickory, Red Maple, Sugar Maple, Black Birch, Ash, Black Locust, occasionally White Birch, etc.
The chart is not always spot-on, but then it's not intended for figuring an individual cord of wood: it's intended to be used to estimate cords of firewood per acre for someone intending to harvest multiple acres. Having said that, we've found it fairly accurate for the 3-cord lots our forester marks.
Thanks for posting the chart. Might not be perfect but better than nothing.
It does make a handy guideline. Over the past 10 years or so, we've harvested about 150 cords of firewood off the group-owned land I mentioned. We keep good records, since we need to report forest management activities each year to stay in Vermont's "Use Value Tax Program". By agreement of the group, anything under 3" diameter must be left in the forest to rot and return nutrients to the soil, so most of us are only harvesting down to a 3 or 4" top, which matches up with the table's "4 inch top" fairly well. We've found our 3-cord marked firewood lots to come out very close to the prediction - usually slightly over 3 cords. Only once has someone complained of being significantly under, and he had only a little over 1.5 cords, so we suspect either he missed some marked trees, or the forester messed up.
