TL;DR
Hardwood = more BTU, longer burn, better coals. Softwood = faster to light, faster to burn, more sparks. The number that matters most is BTU per cord — it tells you how much heat you're actually getting per load of wood. Moisture content matters more than species: wet oak burns worse than dry pine. Never burn treated wood, painted wood, or poison ivy.
Hardwood BTU Rankings
Higher BTU means more heat per piece of wood and longer burn time between loads.
| Species | BTU/Cord (millions) | Coaling Quality | Splitting | Smoke | Notes | |---------|--------------------|-----------------|-----------|----|-------| | Osage orange (hedge apple) | 32.9 | Excellent | Difficult | Low | Highest BTU of any N. American species. Dense, heavy. | | Hickory | 27.7 | Excellent | Moderate | Low | Outstanding coals. Popular for smoking meat. | | Black locust | 27.9 | Excellent | Easy | Low | Splits easily despite density. Very long-burning. | | Apple | 27.0 | Excellent | Moderate | Low, fragrant | Excellent coals and aroma. Ideal for cooking fires. | | White oak | 25.7 | Excellent | Moderate | Low | Benchmark hardwood. Widely available in eastern US. | | Red oak | 24.6 | Good | Easy | Moderate | Burns well; needs thorough seasoning (high water content). | | Sugar maple | 24.0 | Excellent | Moderate | Low | Dense, slow burn. One of the best stove woods. | | Beech | 24.0 | Good | Moderate | Low | Similar to maple. Burns long and hot. | | White ash | 23.6 | Good | Easy | Low | Excellent — can burn slightly green in emergency. Easy to split. | | Black walnut | 22.2 | Good | Easy | Moderate | Good heat. Splits easily. | | Yellow birch | 21.8 | Good | Easy | Low | Good all-around wood. | | Elm | 20.0 | Fair | Very difficult | Moderate | Interlocking grain — very hard to split. | | Cherry | 20.4 | Good | Easy | Low, fragrant | Good heat, pleasant aroma. | | Red maple | 18.6 | Fair | Easy | Moderate | Lower BTU than sugar maple. Burns faster. | | Paper birch | 20.3 | Fair | Easy | Moderate | Burns bright; moderate coals. Bark is excellent fire starter. |
Softwood BTU Rankings
| Species | BTU/Cord (millions) | Coaling Quality | Splitting | Smoke | Notes | |---------|--------------------|-----------------|-----------|----|-------| | Douglas fir | 20.7 | Fair | Easy | Moderate | Highest BTU of common softwoods. Decent stove wood when dry. | | Tamarack/larch | 21.8 | Fair | Easy | Low | Technically a deciduous conifer. Burns more like hardwood. | | Pitch pine | 20.4 | Poor | Easy | Heavy | Very resinous. Good starter but heavy smoke. | | Ponderosa pine | 16.2 | Poor | Easy | Moderate | Low density. Burns fast. Good for quick heating. | | White pine | 15.9 | Poor | Easy | Moderate | Fast ignition. Very short burn times. High spark production. | | Spruce | 15.5 | Poor | Easy | Moderate | Similar to pine. Sparks readily. | | Cedar | 12.2 | Poor | Easy | Fragrant, low | Very low BTU. Burns fast and bright. Good for starting fires. |
Understanding the Numbers
A cord is a stack of wood 4 feet high × 4 feet wide × 8 feet long. A face cord (also called a rick) is typically 1/3 of a full cord — 4 feet high × 8 feet wide × 16 inches deep.
The BTU difference between species is substantial. Burning white pine instead of hickory to heat the same space requires roughly 75% more wood by volume. If you're purchasing firewood or planning how much to cut and store, species selection directly affects how long your supply lasts.
Splitting Difficulty Explained
Easy to split: Ash, birch, locust, cherry, walnut. Straight grain, splits cleanly along the grain with one or two maul strikes.
Moderate: Oak, hickory, maple. Denser wood requires more force. Split when fresh (green wood splits easier than dry for dense species).
Difficult: Osage orange, elm, sycamore. Osage orange is hard enough to damage mauls. Elm's interlocking grain resists splitting in almost any direction — a hydraulic splitter handles elm better than a manual maul.
Knots and crotches: Any species becomes difficult to split at branch junctions. Work around knots when possible. Set problem pieces aside for a hydraulic splitter.
Best Wood by Use Case
Wood stove / heating overnight: Hickory, oak, sugar maple, black locust. Dense hardwoods with excellent coaling — they produce long-lived coals that hold heat between loadings.
Open fireplace: White oak, cherry, apple. Low-smoke species that won't fill the room. Avoid softwoods in open fireplaces — high spark production and poor coaling.
Cooking fires (coal production): Apple, cherry, hickory, oak. These produce long-lasting, even-heat coals. Apple and cherry add mild flavor to food.
Quick ignition / emergency fire starting: Cedar, birch bark, dry softwood. These light fast. Use as kindling or in emergencies when you need fire quickly.
Camp fires / outdoor use: Any dry hardwood. Smoke is less of a concern outdoors. Avoid species with excessive sparks (pine, cedar) if setting up camp directly next to the fire.
Smoking meat: Hickory, apple, cherry, mesquite, alder. Different flavors. See smoking meats article for specifics.
Moisture Content is the Primary Variable
A perfectly selected species burned wet will perform worse than an "inferior" species burned dry. The single most important variable in firewood performance is moisture content.
Seasoned (dry): ≤20% moisture content. Achieved by splitting and stacking with airflow for 6-12 months, depending on species and climate.
Green (fresh-cut): 40-60% moisture content. Burns poorly, produces thick smoke, creates maximum creosote, generates minimal usable heat. The water must be evaporated before combustion can occur.
Checking moisture: A simple wood moisture meter (pin-type) reads moisture content in seconds. Test the cut face of a split piece, not the bark surface. Above 25% = needs more drying time. Below 20% = ready to burn.
Storage for seasoning: Stack off the ground (use pallets or rails), cover the top but leave sides open for airflow. South-facing stacks with afternoon sun dry fastest.
Wood to Never Burn
| Material | Why | |---------|-----| | Pressure-treated lumber (green-tinted, brown-tinted) | Contains copper compounds (ACQ, CCA) or other preservatives. Releases toxic copper and arsenic oxides. | | Railroad ties, utility poles | Treated with creosote or pentachlorophenol. Heavy carcinogenic smoke. | | Plywood, OSB, particleboard | Formaldehyde-based adhesive resins release toxic fumes when burned. | | Painted or stained wood | Lead paint (pre-1978 wood especially), chemical stains, VOCs in finish coatings. | | Driftwood | Salt-soaked wood releases chlorine compounds; salt corrodes stove components and chimney. | | Poison ivy, poison sumac, poison oak | Urushiol in smoke causes severe allergic reaction in airways. Can be fatal to susceptible individuals. | | Moldy or fungus-covered wood | Mold spores in smoke; wood has lost structural integrity and burns poorly. |
When in doubt about the history of a piece of wood (old lumber from a demo site, wood found near industrial areas), don't burn it indoors.
Sources
Frequently Asked Questions
What is the best firewood for heat output?
Osage orange (hedge apple) has the highest BTU output of any North American firewood at approximately 32.9 million BTU per cord. Black locust is a close second at 27.9 million BTU/cord. Among widely available species, white oak (25.7 million BTU/cord) and hickory (27.7 million BTU/cord) are the best commonly available options. Compare to white pine at 15.9 million BTU/cord — burning equivalent heat requires nearly twice the volume of pine as hickory.
Is it safe to burn softwood in a wood stove?
Yes, with precautions. The myth that softwood causes chimney fires is overstated. Creosote formation results from incomplete combustion — primarily from burning any wood wet or at low temperatures — not from softwood specifically. Dry softwood burns hot and clean. The practical problem with softwood is it burns faster, requiring more frequent loading, and it produces more sparks when used in open fireplaces. For wood stoves, dry softwood is acceptable. For open fireplaces, stick to hardwood.
What wood should you never burn?
Never burn: treated lumber (any wood with green, brown, or painted surfaces from preservatives like CCA, ACQ, or creosote-treated railroad ties), plywood or OSB (formaldehyde and adhesive binders release toxic fumes), any wood that has been painted or stained, driftwood (high salt content corrodes stoves and releases chlorine compounds), and poison ivy, poison oak, or poison sumac (urushiol in smoke causes severe respiratory reactions, potentially fatal).