It comes down to density
Wood is mostly cellulose with varying amounts of air trapped in its cell structure. Dense hardwoods like oak, hickory, and black locust pack more solid wood fiber into the same cubic foot than lighter species like white pine or tamarack. More fiber per cubic foot means more fuel per cubic foot, which is why a cord of black locust (roughly 26.8 MMBtu) holds about twice the heat of a cord of white pine (roughly 13.3 MMBtu) at the same seasoned moisture.
Species BTU-per-cord figures on this site follow that same logic — see the full firewood BTU chart for the 11-species comparison, sourced from USDA Forest Service and state extension data. The same density difference also shows up on a scale — see buying firewood by weight instead of volume for how much a cord of each actually weighs.
Where price and heat actually diverge
Softwoods like pine typically sell for less per cord than hardwoods, partly because they are less dense (so a cord is 'lighter' fuel), and partly because they season faster and are often more available regionally. That lower price does track a real drop in heat content, but not always proportionally — which is exactly the gap the price comparator on the homepage is built to catch.
Run any two quotes through the signature price-per-MMBtu tool before assuming the cheaper cord-price is the cheaper heat.
| Species | MMBtu per cord (approx.) |
|---|---|
| Black locust | 26.8 |
| White oak | 24.0 |
| Red oak | 21.3 |
| Green ash | 19.9 |
| White birch | 16.5 |
| White pine | 13.3 |
When pine is genuinely the right buy
Softwoods light faster and burn hotter for shorter bursts, which makes pine and other resinous softwoods good for kindling, shoulder-season fires, or outdoor fire pits where sustained overnight heat isn't the goal. Pine also tends to season faster than dense hardwood, so a pine cord bought in late summer is more likely to be truly ready by winter than an oak cord cut the same day.
For a primary heat source through a full winter, the lower price per cord on softwood is usually offset by needing more cords to deliver the same total heat — run the numbers on price per MMBtu rather than price per cord before deciding.
- Kindling and fire starting, where fast lighting matters more than sustained heat.
- Shoulder-season fires in spring and fall, when a shorter, hotter burn is enough.
- Outdoor fire pits, where overnight heat retention is not the goal.
- Buyers on a tight timeline, since pine seasons faster than dense hardwood.
Frequently asked questions
Does resin in pine make it burn dirtier?
Resinous softwoods can produce more creosote buildup in a chimney if burned unseasoned or in appliances not designed for it — seasoning to the standard ~20% moisture and having the flue inspected regularly addresses most of that concern.
Is a mixed load of hardwood and softwood a bad deal?
Not inherently — it depends entirely on the mix and the price. Ask the seller for an approximate species breakdown and weight it against the BTU table before comparing to an all-hardwood quote.
Why do BTU tables show a range instead of one number per species?
Moisture content, tree growing conditions, and how the tables were measured all introduce some variance — the figures here are averages meant for comparison between species, not lab-precise values for any single log.
